Accessibility Guidelines

Four Principles of Accessibility

  • Perceivable

    Information and user interface components must be presentable to users in ways they can perceive (e.g. alt tags that say what the item actually does, like ‘Submit form Button’).

  • Operable

    User interface components and navigation must be operable (e.g., you must be able to navigate the site using a keyboard as well as a mouse).

  • Understandable

    Information and the operation of user interface must be understandable, (e.g. error messaging on a form should make sense; instead of ‘Invalid field’ messaging, use ‘The Email field must be in a valid format’).

  • Robust

    Content must be robust enough so it can be interpreted reliably by a wide variety of user agents, including assistive technologies. In other words, don’t use tags or code that only certain browsers understand.

Guidelines Checklist

  • Text Alternatives

    Provide alternatives for non-text content (e.g., images) so that the content is accessible for all users.

  • Time-Based Media

    Provide an alternative (e.g., transcript) for time-based media (e.g., audio/video) that presents equivalent information, or link to textual information with comparable information for non-prerecorded media).

  • Adaptable

    Create content that can be presented in different ways without losing information or structure.

  • Distinguishable

    Make it easy for users to see and hear content, including separating foreground and background, by using readable fonts, larger font sizes, and highlighted link styling for example.

  • Keyboard Accessible

    Make all functionality available from a keyboard.

  • Timing

    Provide enough time for users to read and use content.

  • Seizures

    Do not include design elements that are known to cause seizures (e.g., rapid flashing).
  • Navigable

    Provide multiple ways to allow users to navigate content including obvious/prominent links and other techniques.

  • Readable

    Make text content readable and understandable via styling and other techniques.

  • Predictable

    Make web pages appear and operate in predictable ways.

  • Input Assistance

    Assist users with web experience, correct mistakes and describe errors in text.

  • Compatible

    Maximize compatibility with current and future user agents, including assistive technologies.