This page lists mobile examples from Implementing UAAG 2.0: A guide to understanding and implementing User Agent Accessibility Guidelines 2.0. It includes the guidelines, success critieria, and intent to provide context for the mobile examples. For background, see the UAAG Overview.
These examples show how web browsers that follow UAAG benefit people with disabilities using the Web on mobile devices.
Browser support is just one aspect of mobile accessibility. W3C WAI's broader work related to mobile accessibility is introduced in Mobile Accessibility.
The user can have all recognized non-text content replaced by alternative content, placeholders, or both. (Level A)
Note: At level A, the user agent can specify that an alternative content or placeholder replace the non-text content. At level AA success criterion 1.1.3 requires that the user can specify one format or placeholder to be used. At level AAA success criterion 1.1.5 requires that the user can specify a cascade order of types of alternative content to be used.
For each type of non-text content, the user can specify a type of alternative content that, if present, will be rendered by default. (Level AA)
For recognized on-screen alternative content for time-based media (e.g. captions, sign language video), the following are all true: (Level AA)
Note: Depending on the screen area available, the display of the primary time-based media may need to be reduced in size to meet this requirement.
For each type of non-text content, the user can specify the cascade order in which to render different types of alternative content when preferred types are not present. (Level AAA)
The user can configure recognized alternative content for time-based media (e.g. captions, sign language video) as follows: (Level AAA)
Note 1: Depending on the screen area available, the display of the primary time-based media may need to be reduced in size or hidden to meet this requirement.
Note 2: Implementation may involve displaying alternative content for time-based media in a separate viewport, but this is not required.
The user can specify that the following classes be highlighted so that each is uniquely distinguished: (Level A)
The user can globally set any or all of the following characteristics of visually rendered text content, overriding any specified by the author or user agent defaults: (Level A)
If synthesized speech is produced, the user can specify the following: (Level A)
If synthesized speech is produced, the user can specify the following if offered by the speech synthesizer: (Level AA)
Note: Because the technical implementations of text to speech engines vary (e.g., formant-based synthesis or concatenative synthesis), a specific engine may not support varying pitch or pitch range. A user agent will expose the availability of pitch and pitch range control if the currently selected or installed text to speech engine offers this capability.
The user can adjust all of the speech characteristics offered by the speech synthesizer. (Level AAA)
If the user agent supports a mechanism for authors to supply stylesheets, the user agent also provides a mechanism for users to supply stylesheets. (Level A)
If user style sheets are supported, then the user can enable or disable user stylesheets for: (Level A)
If the user agent supports a mechanism for authors to supply stylesheets, the user can disable the use of author style sheets on the current page. (Level A)
The user can save copies of the stylesheets referenced by the current page, in order to edit and load the copies as user stylesheets. (Level AA)
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)
The user can determine the viewport's position relative to the full extent of the rendered content. (Level A)
The user can rescale content within graphical viewports as follows: (Level A)
To the extent possible, the point of regard remains visible and at the same location within the viewport when the viewport is resized, when content is zoomed or scaled, or when content formatting is changed. (Level A)
For user agents that implement a viewport history mechanism (e.g. "back" button), the user can return to any state in the viewport history that is allowed by the content, including a restored point of regard, input focus and selection. (Level AA)
The user can specify whether author content can open new top-level viewports (e.g. windows or tabs). (Level AA)
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)
The user can request that when reflowable content in a graphical viewport is rescaled, it is reflowed so that one dimension of the content fits within the height or width of the viewport. (Level AA)
Note: User agents are encouraged to allow users to override author instructions not to wrap content (e.g., nowrap).
The user can mark items in a webpage, 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)
Users can view a navigable outline of rendered content composed of labels for important elements, and can move focus efficiently to these elements in the main viewport. (Level AA)
Note: The important elements depend on the web content technology, but may include headings, table captions, and content sections.
The user can view all source text that is available to the user agent. (Level AAA)
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)
Every viewport has an active or inactive keyboard focus at all times. (Level A)
The user can specify that focus and selection can be moved without causing further changes in focus, selection, or the state of controls, by either the user agent or author content. (Level A)
The user agent user interface includes mechanisms to make keyboard access more efficient than sequential keyboard access. (Level A)
The user can move the keyboard focus backwards and forwards through all recognized enabled elements in the current viewport. (Level A)
If the author has not specified a navigation order, the default sequential navigation order is the document order. (Level A)
The user can prevent sequential navigation from wrapping the focus at the beginning or end of a document, and can request notification when such wrapping occurs. (Level AA)
The user can navigate directly to any important elements (e.g. structural or operable) in rendered content. (Level AA)
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)
The user can move directly to and activate any enabled element in rendered content. (Level A)
The user can have any direct commands in the user agent 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)
The user can override any keyboard shortcut including recognized author supplied shortcuts (e.g. accesskeys) and user agent user interface controls, except for conventional bindings for the operating environment (e.g. arrow keys for navigating within menus). The rebinding options must include single-key and key-plus-modifier keys if available in the operating environment. The user must be able to save these settings beyond the current session. (Level AA)
The user agent provides at least the following types of structural navigation, where the structure types exist:(Level AA)
The user can configure sets of important elements (including element types) for structured navigation and hierarchical/outline view. (Level AAA)
The user can discover recognized input methods explicitly associated with an element, and activate those methods in a modality independent manner. (Level AA)
User agent accessibility preference settings persist between sessions. (Level A)
The user can restore all preference settings to default values. (Level A)
The user can save and retrieve multiple sets of user agent preference settings. (Level AA)
The user can adjust any preference settings required to meet the User Agent Accessibility Guidelines (UAAG) 2.0 from outside the user agent user interface. (Level AA)
The user can transfer all compatible user agent preference settings between computers. (Level AAA)
The user can customize which user agent commands, functions, and extensions are displayed within the user agent's user interface as follows:(Level AA)
Guideline 2.11 and its success criteria only apply to images, animations, video, audio, etc. that the user agent can recognize.
The user can render 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)
If an input device is supported by the platform, all user agent functionality other than text input can be operated using that device. (Level AA)
If an input device is supported by the platform, all user agent functionality including text input can be operated using that device. (Level AAA)
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 can require user confirmation to proceed. (Level A)
All features of the user agent that meet User Agent Accessibility Guidelines 2.0 success criteria are documented. (Level A)
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)
If a component of the user agent user interface cannot be exposed through platform accessibility services, then the user agent provides an equivalent alternative that is exposed through the platform accessibility service. (Level A)
If the user agent contains non-web-based user interfaces, then those user interfaces follow user interface accessibility guidelines for the platform. (Level A)