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Accessibility Guide

Practices and tools for making products and services accessible to everyone.


This checklist helps developers identify potential accessibility issues affecting their websites or applications. It’s broken down into three sections of decreasing importance: A, B, and C. Please check and address these issues in the order in which they appear:

  • A — Critical issues that’ll cause serious problems and/or stop most users of assistive technology from using the site.
  • B — Issues that may cause problems or increased frustration for certain users.
  • C — Minor issues that’ll cause problems or frustration for a small number of users

It’s important to note, while B and C are noted as less critical, they’re still required to be truly Section 508 compliant. This checklist should be used as a reference for development and isn’t a substitute for compliance checks by a Section 508 coordinator.

A — Critical

  1. Site is keyboard accessible
    • All interactions can be accessed with a keyboard
  2. Site is free of keyboard traps
    • The keyboard focus is never trapped in a loop
  3. All form inputs have explicit labels
  4. All relevant images use an img tag
  5. All images have alt attributes
  6. Multimedia is tagged
    • All multimedia has appropriate captioning and audio description
  7. Text has sufficient color contrast
    • All text has a contrast ratio of 4.5:1 with the background

B — Less Critical

  1. Site never loses focus
    • Focus is always visible when moving through the page with the keyboard
  2. Tab order is logical
  3. Form instructions are associated with inputs
  4. Site doesn’t timeout unexpectedly
    • Identify elements that may “timeout” and verify that the user can request more time
  5. Tables are coded properly
    • Tables have proper headers and column attributes
  6. Headings are nested properly
    • Heading elements are nested in a logical way

C — Minor

  1. Frames are named
    • All frames have a name element
  2. Flashing elements are compliant
    • Elements that flash on screen do so at a rate of less than 3 Hz
  3. Language is set
    • The language for the page is set
    • The language for sections on the page that differ from the site language are set
  4. CSS isn’t required to use the page
    • The page makes sense with or without CSS
  5. Links are unique and contextual
    • All links can be understood taken alone (for example, “read more about 508”)
  6. Page titles are descriptive
  7. Required plugins are linked on the page

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