Summary
Guidelines categorised must or must not are best practices that can easily be tested with specific criteria that is not subjective and is technologically possible to achieve with current assistive technology on mobile devices.
Guidelines categorised as should or should not are less testable but considered core to accessible mobile website and apps.
Principles:
- Use platform and web standards as intended
- Use standard interface controls where possible
- Support platform accessibility
Audio and video
Alternatives for audio and visual contentmust Alternative delivery, such as subtitles, sign language, audio description and transcripts, must be provided with embedded media when available.
Autoplaymust not Audio must not play automatically unless the user is made aware this will happen or a pause/stop/mute button is provided.
Metadatashould Relevant metadata should be provided for all media.
Volume controlshould Separate volume controls should be provided for background music, ambient sounds, narrative and editorially significant sound effects.
Audio conflictshould not Narrative audio in games or interactive media should not talk over or conflict with native assistive technology.
Design
Colour contrastmust The colour of text and background content must have sufficient contrast.
Colour and meaningmust not Information or meaning must not be conveyed by colour only.
Styling and readabilitymust Core content must still be accessible when styling is unsupported or removed.
Touch target sizemust Touch targets must be large enough to touch accurately.
Spacingshould An inactive space should be provided around actionable elements.
Content resizingmust Users must be able to control font sizing and user interface (UI) scaling.
Actionable elementsmust Links and other actionable elements must be clearly distinguishable.
Visible focusmust When focused, all actionable and focusable elements must have a visible state change.
Consistencyshould A user’s experience should be consistent.
Choicemust Interfaces must provide multiple ways to interact with content.
Adjustabilityshould Interactive media, including games, should be adjustable for user ability and preference.
Flickermust not Content must not visibly or intentionally flicker or flash more than three times in any one-second period.
Editorial
Consistent labellingshould Consistent labelling should be used across websites and native applications as well as within websites and applications.
Indicating languagemust The language of a page or app must be specified, and changes in language must be indicated.
Instructionsshould When needed, additional instructions should be provided to supplement visual and audio cues.
Focus
Focusable elementsmust All interactive elements must be focusable and inactive elements must not be focusable.
Keyboard trapmust not There must not be a keyboard trap.
Content ordermust Content order must be logical.
Focus ordermust Actionable content must be navigable in a meaningful sequence.
Changing focusmust not Focus or context must not automatically change during user input.
Appropriate triggersmust Actions must be triggered when appropriate for the type of user interaction.
Alternative input methodsmust Alternative input methods must be supported.
Forms
Labelling form controlsmust All form controls must be labelled.
Input Formatmust A default input format must be indicated and supported.
Form Layoutmust Labels must be placed close to the relevant form control, and laid out appropriately.
Grouping form elementsmust Controls, labels, and other form elements must be properly grouped.
Images
Images of textshould Images of text should be avoided.
Background imagesmust Background images that convey information or meaning must have an additional accessible alternative.
Links
Descriptive linksmust Link and navigation text must uniquely describe the target or function of the link or item.
Links to alternative formatsmust Links to alternative formats must indicate that an alternative is opening.
Combining repeated linksmust Repeated links to the same resource must be combined within a single link.
Notifications
Inclusive notificationsmust Notifications must be both visible and audible.
Standard operating system notificationsshould Standard operating system notifications should be used where available and appropriate.
Error messages and correctionmust Clear error messages must be provided.
Feedback and assistanceshould Non-critical feedback or assistance should be provided when appropriate.
Scripts and dynamic content
Progressive functionalitymust Apps and websites must be built to work in a progressive manner that ensures a functional experience for all users.
Controlling mediamust Media that updates or animated content must have a pause, stop or hide control.
Page refreshesmust not Automatic page refreshes must not be used without warning.
Timeoutsmust A timed response must be adjustable.
Input controlshould Interaction input control should be adaptable.
Structure
Unique page/screen titlesmust All pages or screens must be uniquely and clearly identifiable.
Headingsmust Content must provide a logical and hierarchical heading structure, as supported by the platform.
Containers and landmarksshould Containers should be used to describe page/screen structure, as supported by the platform.
Grouped elementsmust Controls, objects and grouped interface elements must be represented as a single accessible component.
Text equivalents
Alternatives for non-text contentmust Alternatives must briefly describe the editorial intent or purpose of the image, object, or element.
Decorative contentmust Decorative images must be hidden from assistive technology.
Tooltips and supplementary informationmust not Tooltips must not repeat link text or other alternatives.
Roles, traits and propertiesmust Elements must have accessibility properties set appropriately.
Visual formattingmust not Visual formatting alone must not be used to convey meaning.
Recommendations
Offer a core accessible website
Use progressive enhancement
Link mobile and desktop sites
Minimise text fields
