Mobile accessibility checklist

Colour

• Colour contrast MUST comply with WCAG 2.0 AA level requirements:
  • Contrast ratio of 4.5:1 for normal text (less than 18 point or 14 point bold.)
  • Contrast ratio of 3:1 for large text (at least 18 point or 14 point bold.)
• Information conveyed via colour MUST be also available by other means too (underlined text for links, etc.)

Visibility

• Content hiding techniques such as zero opacity, z-index order and off-screen placement MUST NOT be used exclusively to handle visibility.
• Everything other than the currently visible screen MUST be truly invisible (especially relevant for single page apps with multiple cards):
  • USE the hidden attribute or visibility or display style properties.
  • Unless absolutely unavoidable, aria-hidden attribute SHOULD NOT be used.

Focus

• All activatable elements MUST be focusable:
  • Standard controls such as links, buttons, and form fields are focusable by default.
  • Non-standard controls MUST have an appropriate ARIA Role assigned to them, such as button, link, or checkbox.
• Focus should be handled in a logical order and consistent manner.

Text Equivalents

• Text equivalent MUST be provided for every non-strictly presentational non-text element within the app.
  • Use alt and title where appropriate (see Steve Faulkner's post about Using the HTML title attribute for a good guide.)
  • If the above attributes are not applicable, use appropriate ARIA Properties such as aria-label, aria-labelledby, or aria-describedby.
• Images of text MUST be avoided.
• All form controls MUST have labels (<label> elements) for the benefit of screen reader users.

Handling State

• Standard controls such as radio buttons and checkboxes are handled by the operating system. However, for other custom controls state changes must be provided via ARIA States such as aria-checked, aria-disabled, aria-selected, aria-expanded, and aria-pressed.

General Guidelines

• An app title MUST be provided.
• Headings MUST not break hierarchical structure

  <h1>Top level heading</h1>
    <h2>Secondary heading</h2>
    <h2>Another secondary heading</h2>
      <h3>Low level heading</h3>

• ARIA Landmark Roles SHOULD be used to describe an app or document structure, such as banner, complementary, contentinfo, main, navigation, search.
• Touch event handlers MUST only be triggered on the touchend event.
• Touch targets MUST be large enough for the user to interact with (see the BBC Mobile Accessibility Guidelines for useful touch target size guidelines.)