WCAG
The pages, documents and media people use need accessible content and interactions.
Explore WCAG 2.2 →REFERENCE / BROWSERS · PLAYERS · READERS
Explore UAAG 2.0
Build an environment people can control. Explore guidance for the software that retrieves, presents and helps people interact with web content—from configurable reading to keyboard navigation and assistive technology support.
W3C WORKING GROUP NOTE
A reference for user-agent design.
15 December 2015
Source checked 15 September 2026.
UAAG 2.0 did not become a W3C Recommendation. Its Recommendation-track work closed before Candidate Recommendation, with insufficient resources for formal testing among the reasons.
Read the published status →THE ACCESSIBILITY CHAIN
What does the user agent make possible?
UAAG
Browsers, players, readers and relevant extensions need usable controls, adaptable presentation and reliable access to content.
Explore this reference ↓ATAG
Authoring tools need accessible interfaces and support for producing accessible content.
Explore ATAG 2.0 →These responsibilities can overlap. A web-based media player has a content interface as well as user-agent behavior; a tool that also edits content can involve ATAG. WAI-ARIA supplies semantics used by user agents and assistive technologies. Read the UAAG–WCAG relationship and user-agent definition when deciding scope.
Five principles. Twenty-six design questions.
Use a principle to orient your review, then open a criterion for its exact source text, including notes and exceptions. Each guideline has an original plain-language explanation, a review activity and an example.
The inventory contains 51 fixed Level A, 48 fixed Level AA and 12 fixed Level AAA criteria, plus 5.1.1, which has different requirements at A, AA and AAA. It appears in every level filter and is marked “Level-dependent.” Filtering or completing a learning activity does not establish conformance.
FIND / READ / APPLY
The UAAG 2.0 reference
AAA requirements only is a study filter. AAA conformance also includes all applicable A and AA requirements.
112 criteria across 26 guidelines.
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PRINCIPLE 1
Perceivable
Make output available in forms people can perceive and configure.
GUIDELINE 1.1
Provide access to alternative content
Make available alternatives usable. Captions, descriptions and text alternatives need discoverable controls and a readable presentation in the user agent.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Use a media sample containing captions and another alternative. Find the available options, enable them with the keyboard, resize the view, and check whether either the controls or important video content becomes obscured.
A concrete example
A player gives captions their own adjustable region below the video; users can enlarge the text while keeping playback controls reachable.
1.1.1 Render Alternative Content
W3C source excerpt · Working Group Note, 15 December 2015
The user can choose to render any type of recognized alternative content that is present for a content element. (Level A)
- Note: It is recommended that the user agent allow the user to choose whether the alternative content replaces or supplements the original content element.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.1.2 Indicate Unrendered Alternative Content
W3C source excerpt · Working Group Note, 15 December 2015
The user can specify that indicators be displayed along with rendered content when recognized unrendered alternative content is present. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.1.3 Replace Non-Text Content
W3C source excerpt · Working Group Note, 15 December 2015
The user can request a placeholder that incorporates recognized text alternative content instead of recognized non-text content, until explicit user request to render the non-text content. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.1.4 Facilitate Clear Display of Alternative Content for Time-based Media
W3C source excerpt · Working Group Note, 15 December 2015
For recognized on-screen alternative content for time-based media (e.g. captions, sign language video), the following are all true: (Level A)
- Don't obscure controls: Displaying time-based media alternatives doesn't obscure recognized controls for the primary time-based media.
- Don't obscure primary media: The user can specify that displaying time-based media alternatives doesn't obscure the primary time-based media.
- Note: Depending on the screen area available, the display of the primary time-based media can need to be reduced in size to meet this requirement.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.1.5 Provide Configurable Alternative Content Defaults
W3C source excerpt · Working Group Note, 15 December 2015
The user can specify which type(s) of alternative content to render by default for each type of non-text content, including time based media. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.1.6 Use Configurable Text for Time-based Media Captions
W3C source excerpt · Working Group Note, 15 December 2015
For recognized on-screen alternative content for time-based media (e.g. captions, sign language video), the user can configure recognized text within time-based media alternatives (e.g. captions) in conformance with 1.4.1. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.1.7 Allow Resize and Reposition of Time-based Media Alternatives
W3C source excerpt · Working Group Note, 15 December 2015
The user can configure recognized alternative content for time-based media (e.g. captions, sign language video) as follows: (Level AAA)
- Resize: The user can resize alternative content for time-based media to at least 50% of the size of the top-level viewports.
- Reposition: The user can reposition alternative content for time-based media to two or more of the following: above, below, to the right, to the left, and overlapping the primary time-based media.
- Note 1: Depending on the screen area available, the display of the primary time-based media can need to be reduced in size or hidden to meet this requirement.
- Note 2: Implementation can involve displaying alternative content for time-based media in a separate viewport, but this is not required.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 1.2
Repair missing content
Expose useful information when content is missing. Assistive technology may help repair missing alternatives when the user agent exposes the information it has about an object.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Use a test page with a missing image alternative. Inspect which available object information is exposed through the accessibility interface. Record what the assistive technology can and cannot obtain.
A concrete example
A browser exposes an image’s available metadata to an assistive tool. A guessed label is kept distinguishable from an author-provided description.
1.2.1 Support Repair by Assistive Technologies
W3C source excerpt · Working Group Note, 15 December 2015
If text alternatives for non-text content are missing or empty, the user agent doesn't attempt to repair the text alternatives by substituting text values that are also available to assistive technologies (e.g. image file name). (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 1.3
Provide highlighting for selection, keyboard focus, enabled elements, visited links
Make focus and interaction states distinguishable. People need to locate the current focus, selection and actionable content, including when they choose different colors.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Navigate a page with links and form controls. Change focus and selection appearance through the available settings; compare focused, selected, visited and unvisited states.
A concrete example
A reader lets someone select a thicker focus border while choosing a separate selection background. Both remain visible over the content.
1.3.1 Distinguishable Highlighting
W3C source excerpt · Working Group Note, 15 December 2015
The user can have the following types of content uniquely highlighted, overriding any values specified by the author: (Level A)
- Selection
- In-page search results
- Active keyboard focus (indicated by focus cursors and/or text cursors)
- Unvisited links
- Visited links
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.3.2 Highlighting Options
W3C source excerpt · Working Group Note, 15 December 2015
The user can set all of the following characteristics of selection highlighting, overriding any values specified by the author: (Level AA)
- Foreground color
- Background color
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.3.3 Highlighting Active Keyboard Focus
W3C source excerpt · Working Group Note, 15 December 2015
The user can set all of the following characteristics of active keyboard focus highlighting, overriding any values specified by the author: (Level AA)
- Foreground color
- Background color
- Border (color, style, and thickness)
- Text cursor blink rate
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.3.4 Distinguishing Enabled Elements
W3C source excerpt · Working Group Note, 15 December 2015
The user can set all of the following characteristics of enabled element highlighting, overriding any values specified by the author: (Level AA)
- Foreground color
- Background color
- Border (color, style, and thickness)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.3.5 Distinguishing Enabled Elements
W3C source excerpt · Working Group Note, 15 December 2015
The user can set all of the following characteristics for visited links and separately for unvisited links, overriding any values specified by the author: (Level AA)
- Foreground color
- Underline
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 1.4
Provide text configuration
Let users choose how text is presented. Text settings should support the reader’s own needs across content and relevant element types.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Try the available text size, font, spacing and color controls on a long article and a form. Check whether configuration persists, overrides author choices where specified, and remains useful in print.
A concrete example
A reading application remembers larger text and generous line spacing, then offers a print view that keeps those choices.
Read the guideline’s source notes
Note 1: The success criteria in guideline 1.4 can be met through user stylesheets. For platforms without user stylesheets, text configuration needs to be provided to users through the user agent's main user interface or via an add-on.
Note 2: Users have varying needs for text size and spacing. Therefore, it’s recommended that user agents provide a wider range of values, and a greater number of increments, to allow the user to adjust the view for their current task.
1.4.1 Basic text formatting (Globally)
W3C source excerpt · Working Group Note, 15 December 2015
The user can globally set all of the following characteristics of visually rendered text content: (Level A)
- Text scale with preserved size distinctions (e.g. keeping headings proportional to main font)
- Text color and background color, choosing from all platform color options
- Font family, choosing from all installed fonts
- Line spacing, choosing from a range with at least three values up to at least 2 times the default
- Text style, choosing to turn on/off underline, italic, bold
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.4.2 Basic text formatting (by Element)
W3C source excerpt · Working Group Note, 15 December 2015
The user can set all of the following characteristics of visually rendered text content for text element types including at least headings, input fields, and links: (Level AA)
- Text size (e.g. 18 point) or scale (e.g. 150%)
- Text color and background color, choosing from all platform color options
- Font family, choosing from at least all installed fonts
- Line spacing, choosing from a range with at least three values up to at least 2 times the default
- Text style, choosing to turn on/off underline, italic, bold
- Margins around blocks of text
- Borders
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.4.3 Blocks of text (Globally)
W3C source excerpt · Working Group Note, 15 December 2015
The user can globally set all of the following characteristics of visually rendered blocks of text: (Level AA)
- Character spacing, choosing from a range with at least 5 values
- Justification (left or right, including turning off full justification)
- Margins around blocks of text
- Borders
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.4.4 Configured and Reflowed Text Printing
W3C source excerpt · Working Group Note, 15 December 2015
The user can print the rendered content, and the following are all true: (Level AA)
- any visual, non-time-based, rendered content can be printed
- the user can choose between available printing devices
- the user can have content printed as it is rendered on screen, reflecting any user scaling, highlighting, and other modifications
- the user can have printed content reflow as if the top-level viewports had been resized to match the horizontal dimension of the printing device's printable area
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.4.5 Default to platform text settings
W3C source excerpt · Working Group Note, 15 December 2015
The user can specify that platform text settings be used as the default values for text configuration. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.4.6 Advanced text formatting
W3C source excerpt · Working Group Note, 15 December 2015
The user can globally set all of the following characteristics of visually rendered blocks of text: (Level AAA)
- Capitalization (overriding upper case and small caps style)
- Word-breaking properties (e.g. auto-hyphenation)
- Word spacing (choosing from a range of at least 5 values)
Note: This success criterion does not apply to text entered as all caps. Content authors are encouraged to use styles instead of typing text as all caps.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 1.5
Provide volume configuration
Keep audio volume under the user’s control. The user agent should expose volume control that works alongside other audio on the platform.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Play a short, nonessential audio sample. Adjust and mute it using the user agent, then check whether other application audio can remain audible.
A concrete example
A person lowers a video’s volume while keeping their screen reader audible enough to navigate the player.
1.5.1 Global Volume
W3C source excerpt · Working Group Note, 15 December 2015
The user can adjust the volume of each audio track independently of other tracks, relative to the global volume level set through operating environment mechanisms. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 1.6
Provide synthesized speech configuration
Make built-in speech adjustable. When the user agent provides synthesized speech, people need control of its voice, pace and presentation.
Explore this guideline Original A11y.mv learning activity
Try a review activity
If speech output exists, locate its voice, rate and volume settings. Try a paragraph containing abbreviations and punctuation; record which pronunciation and speech options are available.
A concrete example
A reader offers a slower voice and a punctuation setting for proofreading, with a faster saved configuration for ordinary reading.
Read the guideline’s source notes
Note: If browsers provide speech output for mainstream users, they should make the speech configurable enough to be usable by a wide range of individuals. When an add-on adds speech output to the user agent, it becomes part of the user agent, and therefore should meet the requirements of 1.6.
1.6.1 Speech Rate, Volume, and Voice
W3C source excerpt · Working Group Note, 15 December 2015
If synthesized speech is produced, the user can specify the following: (Level A)
- Speech rate
- Speech volume (independently of other sources of audio)
- Voice, when more than one voice is available
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.6.2 Speech Pitch and Range
W3C source excerpt · Working Group Note, 15 December 2015
If synthesized speech is produced, the user can specify the following if offered by the speech synthesizer: (Level AA)
- Pitch (average frequency of the speaking voice)
- Pitch range (variation in average frequency)
- Note: Because the technical implementations of text to speech engines vary (e.g. formant-based synthesis, concatenative synthesis), a specific engine may not support varying pitch or pitch range. A user agent should expose the availability of pitch and pitch range control if the currently selected or installed text to speech engine offers this capability.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.6.3 Synthesized Speech Features
W3C source excerpt · Working Group Note, 15 December 2015
If synthesized speech is produced, the following features are provided: (Level AA)
- User-defined add-ons to the synthesized speech dictionary.
- "Spell-out": text is spelled one character at a time, or according to language-dependent pronunciation rules.
- At least two ways of speaking numerals: spoken as individual digits and punctuation (e.g. "one two zero three point five" for 1203.5 or "one comma two zero three point five" for 1,203.5), and spoken as full numbers are spoken (e.g. "one thousand, two hundred and three point five" for 1203.5).
- At least two ways of speaking punctuation: spoken literally, and with punctuation understood from speech characteristics like pauses.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.6.4 Synthesized Speech Language
W3C source excerpt · Working Group Note, 15 December 2015
If synthesized speech is produced and more than one language is available, the user can change the language. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.6.5 Advanced Speech Characteristics
W3C source excerpt · Working Group Note, 15 December 2015
If synthesized speech is produced, the user can adjust all of the speech characteristics provided by the speech synthesizer. (Level AAA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 1.7
Enable configuration of user stylesheets
Support the user’s own style choices. User style sheets offer a reusable way to adapt content presentation beyond a small settings panel.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Load a simple user stylesheet in a test environment. Check activation, disabling and access to style choices without losing the current reading position.
A concrete example
A user switches between a comfortable reading stylesheet and the author’s layout when a complex page needs a different strategy.
1.7.1 Disable Author Stylesheets
W3C source excerpt · Working Group Note, 15 December 2015
If the user agent supports a mechanism for author styles, the user can disable the use of author styles on the current page. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.7.2 Support User Stylesheet or User Style Modification Mechanism
W3C source excerpt · Working Group Note, 15 December 2015
If the user agent supports a mechanism for
author styles, the user agent also provides a mechanism for a user styling to override author styling. (Level A)Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.7.3 Apply User Stylesheets
W3C source excerpt · Working Group Note, 15 December 2015
If user styles are supported, then the user can enable or disable user styles for: (Level A)
- All pages on specified websites, or
- All pages
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.7.4 Save Copies of Stylesheets
W3C source excerpt · Working Group Note, 15 December 2015
The user can save copies of the stylesheets referenced by the current page. This allows the user to edit and load the copies as user stylesheets. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 1.8
Help users to orient within, and control, windows and viewports
Preserve orientation while views change. Zooming, resizing, opening windows and going back should leave people able to find where they were.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Read partway through a long page, focus a link, zoom and resize. Follow the link and return. Record what happens to reading position, focus, form entries and new windows.
A concrete example
A browser returns to the same focused link and scroll position after Back, so the person can continue the task without searching again.
1.8.1 Highlight Viewport
W3C source excerpt · Working Group Note, 15 December 2015
The user can have the viewport with the input focus be highlighted. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.2 Move Viewport to Selection and Focus
W3C source excerpt · Working Group Note, 15 December 2015
When a viewport's selection or input focus changes, the viewport's content moves as necessary to ensure that the new selection or input focus location is at least partially in the visible portion of the viewport. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.3 Provide Viewport Scrollbars
W3C source excerpt · Working Group Note, 15 December 2015
When the
rendered content extends beyond the viewport dimensions, users can have graphical viewports include scrollbars, overriding any values specified by the author. (Level A)Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.4 Indicate Viewport Position
W3C source excerpt · Working Group Note, 15 December 2015
The user can determine the viewport's position relative to the full extent of the rendered content. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.5 Allow Zoom
W3C source excerpt · Working Group Note, 15 December 2015
The user can rescale content within top-level graphical viewports as follows: (Level A)
- Zoom in: to 500% or more of the default size
- Zoom out: to 10% or less of the default size, so the content fits within the height or width of the viewport
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.6 Maintain Point of Regard
W3C source excerpt · Working Group Note, 15 December 2015
The point of regard remains visible within the viewport when the viewport is resized, when content is zoomed or scaled, or when content formatting is changed. (Level A)
- Note: When the point of regard is larger than the viewport, the user agent keeps visible the beginning of the point of regard according to the current language's reading order (e.g. top-left in English)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.7 Customize Viewport Highlighting
W3C source excerpt · Working Group Note, 15 December 2015
When highlighting viewports as specified by 1.8.1 Highlight Viewport, the user can customize attributes of the viewport highlighting mechanism (e.g. color and width of borders). (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.8 Allow Viewport Resize
W3C source excerpt · Working Group Note, 15 December 2015
The user can resize viewports within restrictions imposed by the platform, overriding any values specified by the author. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.9 Provide Viewport History
W3C source excerpt · Working Group Note, 15 December 2015
For user agents that implement a history mechanism for top-level viewports (e.g. "back" button), the user can return to any state in the viewport history that is allowed by the content, including: (Level AA)
- restored point of regard
- input focus, and
- user's form field entries
- Note: It is recommended that selection also be restored.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.10 Allow Top-Level Viewport Open on Request
W3C source excerpt · Working Group Note, 15 December 2015
The user can specify whether author content can open new top-level viewports (e.g. windows or tabs). (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.11 Allow Top-Level Viewport Focus Control
W3C source excerpt · Working Group Note, 15 December 2015
If new top-level viewports (e.g. windows or tabs) are configured to open without explicit user request, the user can specify whether or not top-level viewports take the active keyboard focus when they open. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.12 Allow Same User Interface
W3C source excerpt · Working Group Note, 15 December 2015
The user can specify that all top-level viewports (e.g. windows or tabs) follow the defined user interface configuration. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.13 Multi-Column Text Reflow
W3C source excerpt · Working Group Note, 15 December 2015
The user can specify that recognized multi-column text blocks each be reflowed into a single column. (Level AA)
- Note: Some layouts may become unusable if author-specified layout is overridden. In this case, the user can turn linearization off and try another strategy. It is recommended that user agents provide a convenient way for the user to turn this behavior on and off.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.14 Ignore Fixed Unit Dimensions
W3C source excerpt · Working Group Note, 15 December 2015
The user can have the user agent override author-specified unit dimensions. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.15 Linearize Content
W3C source excerpt · Working Group Note, 15 December 2015
The user can have recognized content rendered as a single column, overriding author-specified formatting of columns, tables, and positioning. (Level AA)
Note: Some layouts may become unusable if author-specified layout is overridden. In this case, the user can turn linearization off and try another strategy. It is recommended that user agents provide a convenient way for the user to turn this behavior on and off.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.8.16 Provide Web Page Bookmarks
W3C source excerpt · Working Group Note, 15 December 2015
The user can mark items in a web page, then use shortcuts to navigate back to marked items. The user can specify whether a navigation mark disappears after a session, or is persistent across sessions. (Level AAA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 1.9
Provide alternative views
Offer another way to inspect content. An outline or source view can make the structure of a long document easier to understand and navigate.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Open a heading-rich document. Find an outline, move to an entry and return to the corresponding content. Separately check whether available source text can be viewed.
A concrete example
A reader’s chapter outline moves focus into the selected heading in the main reading view, rather than only scrolling the screen.
1.9.1 Outline View
W3C source excerpt · Working Group Note, 15 December 2015
Users can view a navigable outline of the headings in rendered content that allows focus to be moved to the corresponding element in the main viewport. (Level AA)
- Note: Note: An outline view might also include other named elements such as document landmarks.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.9.2 Source View
W3C source excerpt · Working Group Note, 15 December 2015
The user can view all source text that is available to the user agent. (Level AAA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 1.10
Provide element information
Make element relationships available. People may need to inspect an element’s name, related labels or place in the document structure.
Explore this guideline Original A11y.mv learning activity
Try a review activity
On a table and a labeled form, inspect a cell and a control. Check access to the available row headers, column headers and calculated accessible names.
A concrete example
A browser inspection feature reports the row and column associated with a table cell, helping the user understand a value in context.
1.10.1 Show Related Elements
W3C source excerpt · Working Group Note, 15 December 2015
The user can access the information from explicitly-defined relationships in the content, including at least the following: (Level AA)
- calculated accessible name for images
- calculated accessible name for controls (e.g. form fields, buttons)
- caption for a table
- row and column labels for a table cell
Original criterion and definitionsW3C explanation and examplesLink to this criterion
1.10.2 Show Element Hierarchy
W3C source excerpt · Working Group Note, 15 December 2015
The user can determine the path of element nodes going from the root element of the element hierarchy to the currently focused or selected element. (Level AAA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
PRINCIPLE 2
Operable
Give people control of navigation, input, preferences and time.
GUIDELINE 2.1
Ensure full keyboard access
Make the whole user agent keyboard operable. Keyboard access includes the user agent’s own menus, settings and content interactions, with reliable focus movement.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Complete an everyday task using only the keyboard: open content, navigate it, change a setting, use a dialog and leave it. Record unreachable functions, traps and focus loss.
A concrete example
A player exposes volume, captions, seeking and fullscreen through keyboard-operable controls with a predictable route back to the content.
2.1.1 Provide Full Keyboard Functionality
W3C source excerpt · Working Group Note, 15 December 2015
All functionality can be operated via the keyboard using sequential or direct keyboard commands that do not require specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints (e.g. free hand drawing). This does not forbid and should not discourage providing other input methods in addition to keyboard operation including mouse, touch, gesture and speech. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.1.2 Has Keyboard Focus
W3C source excerpt · Working Group Note, 15 December 2015
Every viewport has an active or inactive keyboard focus at all times. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.1.3 Avoid Keyboard Traps
W3C source excerpt · Working Group Note, 15 December 2015
If keyboard focus can be moved to a component using a keyboard interface (including nested user agents), then focus can be moved away from that component using only a keyboard interface. If this requires more than unmodified arrow or Tab keys (or standard exit methods like Escape), users are advised of the method for moving focus away. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.1.4 Separate Selection from Activation
W3C source excerpt · Working Group Note, 15 December 2015
The user can specify that focus and selection can be moved without the user agent or author-supplied content further changing focus, selection, or the state of controls. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.1.5 Follow Text Keyboard Conventions
W3C source excerpt · Working Group Note, 15 December 2015
The user agent follows keyboard conventions for the operating environment. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.1.6 Make Keyboard Access Efficient
W3C source excerpt · Working Group Note, 15 December 2015
The user agent user interface includes mechanisms to make keyboard access more efficient than sequential keyboard access. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 2.2
Provide sequential navigation
Support sequential navigation that people can follow. Moving through controls in sequence should keep the destination visible and make navigation behavior understandable.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Use forward and reverse navigation through links and controls, including the final item. Check visible focus, enabled elements and any option that controls wrapping.
A concrete example
A browser lets a person understand whether Tab will continue into browser controls or wrap through the current content.
2.2.1 Sequential Navigation Between Elements
W3C source excerpt · Working Group Note, 15 December 2015
The user can move the keyboard focus backwards and forwards through all recognized enabled elements in the rendered content of the current top-level viewports. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.2.2 Sequential Navigation Between Landmarks
W3C source excerpt · Working Group Note, 15 December 2015
The user can move the keyboard focus backwards and forwards between regions identified by document landmarks.
(Level A)- Note: The user agent might also include other regions, such as viewports, in the sequential navigation.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.2.3 Default Navigation Order
W3C source excerpt · Working Group Note, 15 December 2015
If the author has not specified a navigation order, the user can have the default sequential navigation order be the source order. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.2.4 Options for Wrapping in Navigation
W3C source excerpt · Working Group Note, 15 December 2015
The user can request notification when sequential navigation wraps at the beginning or end of a document, and can prevent such wrapping. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 2.3
Provide direct navigation and activation
Provide efficient routes to frequent actions. Direct commands and shortcuts can reduce the number of steps needed to reach controls or activate content.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Inspect the available direct commands and their labels. Try a common task with shortcuts, then check how a person can discover or configure the relevant commands.
A concrete example
A browser offers discoverable shortcuts to the address field and a content navigation command, reducing repeated sequential movement.
2.3.1 Allow Direct Navigation to Enabled Elements
W3C source excerpt · Working Group Note, 15 December 2015
The user can move keyboard focus directly to any enabled element in the rendered content. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.3.2 Allow Direct Activation of Enabled Elements
W3C source excerpt · Working Group Note, 15 December 2015
The user can, in a single action, move keyboard focus directly to any enabled element in the rendered content and perform an activation action on that element. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.3.3 Present Direct Commands from Rendered Content
W3C source excerpt · Working Group Note, 15 December 2015
The user can have any recognized direct commands in rendered content (e.g. accesskey, landmark) be presented with their associated elements (e.g. Alt+R to reply to a web email). (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.3.4 Present Direct Commands in User Interface
W3C source excerpt · Working Group Note, 15 December 2015
The user can have any direct commands in the UA user interface (e.g. keyboard shortcuts) be presented with their associated user interface controls (e.g. "Ctrl+S" displayed on the "Save" menu item and toolbar button). (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.3.5 Allow Customized Keyboard Commands
W3C source excerpt · Working Group Note, 15 December 2015
The user can remap any keyboard shortcut including recognized author supplied shortcuts (e.g. accesskeys) and UA user interface controls, except for conventional bindings for the operating environment (e.g. arrow keys for navigating within menus). (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 2.4
Provide text search
Make search reveal usable results. Searching should help a person find relevant text, understand matches and move to them in context.
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Try a review activity
Search for repeated text, text split across inline elements, and a phrase in available alternative content. Move forward and backward through results and inspect focus and context.
A concrete example
A reader searches a downloaded transcript and moves the current match into view while keeping earlier and later matches available.
2.4.1 Text Search
W3C source excerpt · Working Group Note, 15 December 2015
The user can perform a search within rendered content, including rendered text alternatives and rendered generated content, for any sequence of printing characters from the document character set. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.4.2 Search Direction
W3C source excerpt · Working Group Note, 15 December 2015
The user can search forward or backward in rendered content. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.4.3 Match Found
W3C source excerpt · Working Group Note, 15 December 2015
When a search operation produces a match, the matched content is highlighted, the viewport is scrolled if necessary so that the matched content is within its visible area, and the user can search from the location of the match. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.4.4 Alert on Wrap or No Match
W3C source excerpt · Working Group Note, 15 December 2015
The user can choose to receive notification when there is no match to a search operation. The user can choose to receive notification when the search continues from the beginning or end of content. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.4.5 Alternative Content Search
W3C source excerpt · Working Group Note, 15 December 2015
The user can perform text searches within alternative content that is text (e.g. text alternatives for non-text content, captions) even when the alternative content is not rendered onscreen. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 2.5
Provide structural navigation
Navigate by meaningful structure. People should be able to move using content structure rather than traversing every item one by one.
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Try a review activity
Use a long document with headings and distinct structural elements. Try structural navigation, checking the target, focus movement and coverage of nested content.
A concrete example
A browser’s heading navigation brings the next section into view so the person can skip a long navigation region.
2.5.1 Provide Structural Navigation by Heading and within Tables
W3C source excerpt · Working Group Note, 15 December 2015
The user agent provides at least the following types of structural navigation, where the structure types are recognized: (Level AA)
- By heading
- By content sections
- Within tables
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 2.6
Configure and store preference settings
Keep accessibility preferences available. People should be able to configure the environment and retrieve useful combinations of settings.
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Try a review activity
Set up a reading preference, close and reopen the user agent, then look for the saved configuration. If profiles exist, check how their names and values can be reviewed and restored.
A concrete example
A shared workstation offers a clearly named reading profile that restores text, input and display settings together.
2.6.1 Allow Persistent Accessibility Settings
W3C source excerpt · Working Group Note, 15 December 2015
User agent accessibility preference settings persist between sessions. (Level A)
- Note: User agents may have a public access setting that turns this off.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.6.2 Allow Restore All to Default
W3C source excerpt · Working Group Note, 15 December 2015
The user can restore all preference settings to default values. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.6.3 Allow Multiple Sets of Preference Settings
W3C source excerpt · Working Group Note, 15 December 2015
The user can save and retrieve multiple sets of user agent preference settings. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.6.4 Allow Preference Changes from outside the User Interface
W3C source excerpt · Working Group Note, 15 December 2015
The user can adjust any preference settings required to meet the User Agent Accessibility Guidelines (UAAG) 2.0 from outside the UA user interface. (Level AAA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.6.5 Make Preference Settings Transferable
W3C source excerpt · Working Group Note, 15 December 2015
The user can transfer all compatible user agent preference settings between devices. (Level AAA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 2.7
Customize display of graphical controls
Let the interface fit the user’s task. Configurable graphical controls can help people reach important functions without unnecessary visual complexity.
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Try a review activity
Review which toolbar controls can be resized or rearranged. Move a frequent action, check its keyboard access and verify that restoring the interface remains straightforward.
A concrete example
A media application lets a user place captions and playback controls where they are easy to locate without removing access to other functions.
2.7.1 Customize Display of Controls for User Interface Commands, Functions, and Add-ons
W3C source excerpt · Working Group Note, 15 December 2015
The user can customize which user agent commands, functions, and add-ons are displayed within the user agent user interface as follows: (Level AA)
- Show: The user can choose to display any controls available within the user agent user interface, including user-installed add-ons. It is acceptable to limit the total number of controls that are displayed onscreen.
- Simplify: The user can simplify the default user interface by choosing to display only commands essential for basic operation (e.g. by hiding some controls).
- Reposition: The user can choose to reposition individual controls within containers (e.g. toolbars or tool palettes), as well as reposition the containers themselves to facilitate physical access (e.g. to minimize hand travel on touch screens, or to facilitate preferred hand access on handheld mobile devices).
- Assign Activation Keystrokes or Gestures: The user can choose to view, assign or change default keystrokes or gestures used to activate controls.
- Reset: The user has the option to reset the containers and controls to their default configuration.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 2.8
Allow time-independent interaction
Allow interaction at the user’s pace. Time limits and timed interactions can interrupt someone who needs more time to read, choose or activate.
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Try a review activity
Identify timed user-agent actions and any controls to pause, extend or adjust them. Use safe test content to check repeated input and simultaneous-key requirements.
A concrete example
A settings notification remains available long enough to read and act on, with another route to the same action if it disappears.
2.8.1 Adjustable Time Limits
W3C source excerpt · Working Group Note, 15 December 2015
The UA user interface does not include time limits or at least one of the following is true: (Level A)
- Turn Off: Users are allowed to turn off the time limit before encountering it; or
- Adjust: Users are allowed to adjust the time limit before encountering it over a wide range that is at least ten times the length of the default setting; or
- Extend: Users are warned before time expires and given at least 20 seconds to extend the time limit with a simple action (e.g. "press the space bar"), and users are allowed to extend the time limit at least ten times; or
- Real-time Exception: The time limit is a required part of a real-time event and no alternative to the time limit is possible; or
- Essential Exception: The time limit is essential and extending it would invalidate the activity; or
- 20 Hour Exception: The time limit is longer than 20 hours.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 2.9
Help users avoid flashing that could cause seizures
Provide ways to avoid flashing content. The user agent has responsibilities for handling flashing risks in its interface and recognized content.
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Try a review activity
Review documented flashing controls and safe test evidence. Check that controls can be found before risky content is displayed; do not expose participants to flashing material to demonstrate a barrier.
A concrete example
A product review records whether recognized risky content can be blocked and which interface animations are covered, using inspection rather than a flashing demonstration.
2.9.1 Three Flashes or Below Threshold
W3C source excerpt · Working Group Note, 15 December 2015
In its default configuration, the user agent does not display any UA user interface components that flashes more than three times in any one-second period, unless the flash is below general flash and red flash thresholds. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.9.2 Three Flashes
W3C source excerpt · Working Group Note, 15 December 2015
In its default configuration, the user agent does not display any UA user interface components that flashes more than three times in any one-second period (regardless of whether not the flash is below the general flash and red flash thresholds). (Level AAA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 2.10
Provide control of time-based media
Give users control over media playback. Playback, automatic activity and audio can compete with reading, navigation or assistive technology.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Use a short safe media sample. Check stop, pause, resume, seeking and relevant playback settings, including what happens when media starts automatically.
A concrete example
A person pauses a tutorial to read captions and inspect a diagram, then resumes without losing the place in the video.
2.10.1 Time-Based Media Load-Only
W3C source excerpt · Working Group Note, 15 December 2015
The user can override the play on load of recognized time-based media content such that the content is not played until explicit user request. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.10.2 Execution Placeholder
W3C source excerpt · Working Group Note, 15 December 2015
The user can request a placeholder instead of executable content that would normally be contained within an on-screen area (e.g. Applet, Flash), until explicit user request to execute. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.10.3 Execution Toggle
W3C source excerpt · Working Group Note, 15 December 2015
The user can turn on/off the execution of dynamic or executable content (e.g. Javascript, canvas, media). (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.10.4 Adjustable Playback Rate for Prerecorded Content
W3C source excerpt · Working Group Note, 15 December 2015
The user can adjust the playback rate of prerecorded time-based media content, such that all of the following are true: (Level AA)
- Playback Rate: The user can adjust the playback rate of the time-based media tracks to between 50% and 250% of real time.
- Pitch: Speech whose playback rate has been adjusted by the user maintains pitch in order to limit degradation of the speech quality.
- Synchronization: Audio and video tracks remain synchronized across this required range of playback rates.
- Reset: The user agent provides a function that resets the playback rate to normal (100%).
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.10.5 Stop/Pause/Resume Time-Based Media
W3C source excerpt · Working Group Note, 15 December 2015
The user can stop, pause, and resume rendered audio and animation content (e.g video, animation, changing text) that lasts three or more seconds at the default playback rate. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.10.6 Navigation of Time-Based Media by Time
W3C source excerpt · Working Group Note, 15 December 2015
If time-based media lasts three or more seconds at the default playback rate, the user can navigate it using a continuous scale and by relative time units. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.10.7 Navigation of Time-Based Media by Semantics
W3C source excerpt · Working Group Note, 15 December 2015
The user can navigate by semantic structure within the time-based media, such as by chapters or scenes present in the media. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
2.10.8 Video Contrast and Brightness
W3C source excerpt · Working Group Note, 15 December 2015
Users can adjust the contrast and brightness of visual time-based media. (Level AAA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 2.11
Support other input devices
Support input beyond a pointer. Alternative input may depend on consistent device behavior and controls that do not require one specific interaction.
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Try a review activity
Identify supported input methods and platform conventions. Repeat a meaningful task with an available alternative input method, documenting the device and configuration.
A concrete example
A user agent works with the platform’s speech commands for named controls while preserving the equivalent keyboard route.
2.11.1 Text Input With Any Device
W3C source excerpt · Working Group Note, 15 December 2015
If an input device is supported by the platform, all user agent functionality including text input can be operated using that device. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
PRINCIPLE 3
Understandable
Support recovery, useful documentation and predictable behavior.
GUIDELINE 3.1
Help users avoid and correct mistakes
Help people prevent and recover from mistakes. Recovery needs include canceling operations, protecting entered information and making consequential actions understandable.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Use test data to examine navigation away from a form, interrupted input and a consequential operation. Check what can be canceled, confirmed or restored.
A concrete example
A browser presents a clear choice before abandoning unsaved form entries and provides a reliable way to return to the task.
3.1.1 Text Entry Undo
W3C source excerpt · Working Group Note, 15 December 2015
The user can reverse recognized text entry actions prior to submission. (Level A)
- Note: Submission can be triggered in many different ways, such as clicking a submit button, typing a key in a control with an onkeypress event, or by a script responding to a timer.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.1.2 Settings Changes can be Reversed or Confirmed
W3C source excerpt · Working Group Note, 15 December 2015
If the user agent provides mechanisms for changing its user interface settings, it either allows the user to reverse the setting changes, or the user agent can require user confirmation to proceed. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.1.3 Retrieval Progress
W3C source excerpt · Working Group Note, 15 December 2015
By default, the user agent shows the state of content retrieval activity. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.1.4 Spell Check
W3C source excerpt · Working Group Note, 15 December 2015
The user can have spelling assistance for editable text in rendered content. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.1.5 Back Button
W3C source excerpt · Working Group Note, 15 December 2015
The user can reverse recognized navigation between web addresses (e.g. standard "back button" functionality). (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.1.6 Form Submission Confirm
W3C source excerpt · Working Group Note, 15 December 2015
The user can specify whether or not recognized form submissions must be confirmed. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.1.7 Form Auto-Fill
W3C source excerpt · Working Group Note, 15 December 2015
The user can have the following information stored and used to auto-fill form fields by request: (Level AA)
- user's name
- user's email address
- user's phone number
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.1.8 Save Form Entries
W3C source excerpt · Working Group Note, 15 December 2015
If the user agent provides a feature to save local versions of web content, then any form fields the user has filled retain any entries in the saved version. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 3.2
Document the user agent user interface including accessibility features
Document accessibility features so people can use them. A feature provides little benefit if people cannot discover its purpose, operation and supported settings.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Ask someone unfamiliar with the product to find keyboard and accessibility documentation. Compare a documented procedure with the current interface and note gaps.
A concrete example
Help content explains how to turn on a reading preference, its effects and how to reverse it, using the same names as the actual controls.
3.2.1 Accessible Documentation
W3C source excerpt · Working Group Note, 15 December 2015
Product documentation is available in a format that meets success criteria of WCAG 2.0 level "A" or greater. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.2.2 Describe Accessibility Features
W3C source excerpt · Working Group Note, 15 December 2015
For each user agent feature that is used to meet UAAG 2.0, at least one of the following is true: (Level A)
- Described in the Documentation: Use of the feature is explained in the user agent's documentation; or
- Described in the Interface: Use of the feature is explained in the UA user interface; or
- Platform Service: The feature is a service provided by an underlying platform; or
- Not Used by Users: The feature is not used directly by users (e.g., passing information to a platform accessibility service).
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.2.3 Document All Features
W3C source excerpt · Working Group Note, 15 December 2015
For each user agent feature, at least one of the following is true: (Level AA)
- Described in the Documentation: Use of the feature is explained in the user agent's documentation; or
- Described in the Interface: Use of the feature is explained in the UA user interface; or
- Platform Service: The feature is a service provided by an underlying platform; or
- Not Used by Users: The feature is not used directly by users (e.g., passing information to a platform accessibility service).
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.2.4 Changes Between Versions
W3C source excerpt · Working Group Note, 15 December 2015
Changes to features that meet UAAG 2.0 success criteria since the previous user agent release are documented. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
3.2.5 Centralized View
W3C source excerpt · Working Group Note, 15 December 2015
There is a dedicated section of the documentation that presents a view of all features of the user agent necessary to meet the requirements of User Agent Accessibility Guidelines 2.0. (Level AAA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
GUIDELINE 3.3
Make the user agent behave in predictable ways
Keep behavior predictable. Changes in focus, interface arrangement or operation should not surprise people as they complete a task.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Repeat a task across tabs and views. Observe changes in focus, control order and configuration; compare behavior after opening and closing an overlay or panel.
A concrete example
Closing a preferences panel returns focus to its opener, and the remaining controls keep their familiar arrangement.
3.3.1 Avoid Unpredictable Focus
W3C source excerpt · Working Group Note, 15 December 2015
The user can prevent focus changes that are not a result of explicit user request. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
PRINCIPLE 4
Programmatic access
Expose information and control to assistive technologies.
GUIDELINE 4.1
Facilitate programmatic access to assistive technology
Work with assistive technology through programmatic interfaces. Visual controls and rendered content need meaningful information and actions exposed through supported accessibility services.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Inspect names, roles, states, values and change notifications using platform accessibility tools. Then verify a real task with an appropriate assistive technology and record versions.
A concrete example
A player exposes a seek control’s current value and updates through the accessibility API so a screen reader can report progress and adjust it.
4.1.1 Support Platform Accessibility Services
W3C source excerpt · Working Group Note, 15 December 2015
The user agent supports relevant platform accessibility services. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
4.1.2 Expose Accessible Properties
W3C source excerpt · Working Group Note, 15 December 2015
For all user interface components (including UA user interface, rendered content, and generated content) the user agent makes available the following properties and any change notifications via a platform accessibility service: (Level A)
- Name, Role, State
- Value
- Selection
- Focus
- Bounding dimensions and coordinates
- Font family of text
- Foreground and background color for text
- Highlighting
- Keyboard commands
- Caret position
- Explicitly defined relationships (e.g. ARIA relationships [ARIA 1.0])
Original criterion and definitionsW3C explanation and examplesLink to this criterion
4.1.3 Provide Equivalent Accessible Alternatives
W3C source excerpt · Working Group Note, 15 December 2015
If UA user interface functionality cannot be exposed through platform accessibility services, then the user agent provides equivalent functionality that can be exposed through the platform accessibility service. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
4.1.4 DOMs Programmatically Available as fallback
W3C source excerpt · Working Group Note, 15 December 2015
If the user agent accessibility API does not provide sufficient information to one or more platform accessibility services, then Document Object Models (DOM), must be made programmatically available to assistive technologies. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
4.1.5 Make Content Interaction Programmatically Available
W3C source excerpt · Working Group Note, 15 December 2015
If the user can interact with content (e.g. by checking a box or editing a text area), the same degree of interaction is programmatically available. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
PRINCIPLE 5
Specifications & conventions
Implement accessibility across web content, native interfaces and platform services.
GUIDELINE 5.1
Comply with applicable specifications and conventions
Connect web standards and platform accessibility. A user agent needs to implement accessibility features in content technologies, its own web interface and native platform components.
Explore this guideline Original A11y.mv learning activity
Try a review activity
Inventory supported technologies and native versus web interface areas. Check their accessibility implementation, alternative-viewer options and issue-reporting route.
A concrete example
A browser review separately records its web-based help, native menus and support for semantic content, then documents a reproducible accessibility issue.
5.1.1 Comply with WCAG
W3C source excerpt · Working Group Note, 15 December 2015
Web-based UA user interfaces meet the WCAG 2.0 success criteria. (Level A to meet WCAG 2.0 Level A success criteria; Level AA to meet WCAG 2.0 Level A and AA success criteria; and Level AAA to meet WCAG 2.0 Level A, AA, and AAA success criteria)
- Note: This success criterion does not apply to native UA user interfaces, but does include any parts of native user agents that are web-based (e.g. help systems). However, it is recommended that developers of native user agent user interfaces follow the Guidance on Applying WCAG 2.0 to Non-Web Information and Communications Technologies (WCAG2ICT) [WCAG2ICT].
Original criterion and definitionsW3C explanation and examplesLink to this criterion
5.1.2 Implement Accessibility Features of Web Content Technology Specifications
W3C source excerpt · Working Group Note, 15 December 2015
Implement the accessibility features of web content technology specifications. Accessibility features are those that are either (Level A):
- Identified as such in the content specifications or
- Allow authors to satisfy a requirement of WCAG 2.0
- Note 1: If a conformance claim is filed, cite the implemented specifications in the conformance claim. See Components of a UAAG 2.0 Conformance Claim - #9 Web Content Technologies.
- Note 2: When a rendering requirement of another specification contradicts a requirement of UAAG 2.0, the user agent can disregard the rendering requirement of the other specification and still satisfy this guideline.
Original criterion and definitionsW3C explanation and examplesLink to this criterion
5.1.3 Implement Accessibility Features of the Platform
W3C source excerpt · Working Group Note, 15 December 2015
If the user agent contains native user interfaces, then those native user interfaces follow user interface accessibility guidelines for the platform. (Level A)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
5.1.4 Allow Content Elements to be Rendered in Alternative Viewers
W3C source excerpt · Working Group Note, 15 December 2015
The user can select content elements and have them rendered in alternative viewers. (Level AA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
5.1.5 Enable Reporting of User Agent Accessibility Faults
W3C source excerpt · Working Group Note, 15 December 2015
The user agent provides a mechanism for users to report user agent accessibility issues. (Level AAA)
Original criterion and definitionsW3C explanation and examplesLink to this criterion
READ THE CONDITIONS
Applicability, evidence and conformance
Scope the actual product
Record the product version, platform, supported content technologies, input and output modes, relevant settings and any required add-ons. Distinguish a browser, player or reader from an application that renders only a developer-constrained set of content.
UAAG’s applicability notes cover retrieved, current and recognized content; optional preferences; platform support; and combinations of features. A feature’s absence needs a reasoned applicability decision, not an automatic pass.
Read levels cumulatively
The Note describes Level A as all applicable A criteria, AA as applicable A and AA, and AAA as all three levels. Criterion 5.1.1 explicitly references WCAG 2.0 and changes with the claimed UAAG level; its wording here is preserved.
A claim requires product and platform details, settings, technology scope and declarations for the criteria. Add-ons have a specific limited-conformance option. A published claim does not imply W3C validation.
The 11 applicability notes W3C source excerpt
- Retrieved Content Only: UAAG 2.0 success criteria only apply to web content that has been retrieved by the user agent (e.g. if a user agent saves bandwidth by retrieving video element content only on demand, then captions associated with that video content do not need to be searchable as per 2.4.5 until the video is retrieved).
- Current Content Only: At any point in time, UAAG 2.0 success criteria only apply to web content that has not been hidden or removed (e.g., a bookmark created as per 1.8.16 will no longer be operable if the content it refers to is hidden or removed).
- Recognized Content Only: UAAG 2.0 success criteria only apply to web content and its behaviors that can be recognized by user agents.
- Optional Settings: Throughout UAAG 2.0, all required behaviors can be provided as optional preference settings unless a success criterion explicitly says otherwise. For example, if a success criterion requires high contrast between foreground text and its background, the user agent can also provide choices with low contrast. While it is preferred to have a required behavior as a default option, it does not need to be, unless the success criterion explicitly says otherwise.
- RFC 2119 language not used: UAAG 2.0 does not use RFC 2119 language (must, may, should) as it is not an interoperable specifications. Note, even if these terms appear from time to time they do not have any RFC 2119 implication.
- Simultaneous satisfaction of success criteria: Users can access all behaviors required by UAAG 2.0 at the same time (e.g. when the user resizes the viewport per 1.8.8, content is reflowed per 1.8.6), except where those behaviors are mutually exclusive.
- Vertical layout languages: When user agents render vertical layout languages (e.g. Mongolian, Han), success criteria normally relating to horizontal rendering should be applied to vertical rendering instead.
- Add-ons (Extensions and Plug-ins): Success criteria can be met by a user agent alone or in conjunction with add-ons, as long as those are:
- discoverable by the user
- no extra cost to the user
- easily installed (i.e. not requiring expert knowledge or editing of configuration files, databases, or registry entries)
- Relationship with operating system or platform: The user agent does not need to implement every behavior itself. A required behavior can be provided by the platform, user agent, user agent add-ons, or potentially other layers. All are acceptable, as long as they are enumerated in the conformance claim.
- Platform limitations: If the platform (hardware or operating system) does not support a capability necessary for a given UAAG 2.0 success criterion, see Components of UAAG 2.0 Conformance Claims #8.
- Override author settings for text configuration: All of the success criteria under guideline 1.4 allow users to override the text characteristics specified by authors, and override user agent defaults.
Three features identified as at risk in 2015
The Note said no implementations had been identified for these three features at publication. This is a historical source-status statement, not a claim about present-day browser support.
- 1.4.5 Default to platform text settings — the Note distinguishes examples of high contrast from text settings.
- 2.2.4 Options for Wrapping in Navigation
- 3.1.6 Form Submission Confirm
Turn a criterion into a useful product review
- Choose a task. For example: open a tutorial, enable captions, adjust text and return to the previous reading position.
- Record the environment. Include the user agent, version, platform, content sample, settings and assistive technology where used.
- Inspect and try it. Pair the original learning activity with the full criterion, definitions and applicability notes.
- Keep reproducible evidence. Record expected behavior, observed behavior, steps and scope. Include people with relevant access needs in product evaluation.
The worksheet can help record observations; its completion is not a UAAG conformance claim. For today’s web-content requirements, use the WCAG 2.2 reference alongside the historical UAAG wording.
Source, status and attribution
This independent implementation-learning application presents all 112 success criteria from User Agent Accessibility Guidelines (UAAG) 2.0, W3C Working Group Note 15 December 2015. The 2015 Note’s formal status language describes it as work in progress. The current WAI UAAG overview describes the guidance as complete and recommends its use, while confirming that W3C does not currently plan to advance it to Recommendation. Check the latest published document for publication context. Source checked 15 September 2026.
W3C source excerpts preserve criterion wording, lists, notes and exceptions. Glossary and reference links lead to the source. Guideline explanations, activities and examples are original A11y.mv material; this page is not an official W3C technical specification.
Copyright © 2015 W3C® (MIT, ERCIM, Keio, Beihang). This software includes material copied from or derived from User Agent Accessibility Guidelines (UAAG) 2.0, W3C Working Group Note 15 December 2015, https://www.w3.org/TR/2015/NOTE-UAAG20-20151215/. W3C Document License (2015).