1. Perceivable

Ensuring that everyone is able to perceive your content even if they access information in a non-typical way.

Users must be able to perceive the information being presented (it can't be invisible to all of their senses)

• Text alternatives for non text content
• Content can be presented in different ways which is separate from style
• Alternative for audio and video content such as captions and/ or transcripts
• Distinguishable content that can be seen and heard

2. Operable

Allowing users to operate your application using a variety of methods and forms of technology

Users must be able to operate the interface (the interface cannot require interaction that a user cannot perform)

• Keyboard accessible functionality
• Enough time to read or use content
• Seizures - avoid designing content which could cause a seizure such as flashing and moving graphics
• Navigable - ways to navigate and find content easily

3. Understandable

All your content should be understandable, clear and concise and you should allow users to explore it at their own pace

Users must be able to understand the information as well as the operation of the user interface (the content or operation cannot be beyond their understanding)

• Readable simplify text content
• Predictable pages which operate in a consistent way
• Input assistance helping users avoid and correct mistakes

4. Robust

Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies.

Users must be able to access the content as technologies advance (as technologies and user agents evolve, the content should remain accessible)

If any of these are not true, users with disabilities will not be able to use the Web or navigate through digital documents.

Compatible with other products including assistive technologies e.g. screen readers and magnifiers