A11ying with Sanna - Web Content Accessibility Guidelines a guide to the accessibility requirements
3 Understandable

3.3.3 Error Suggestion

Conformance level: AA
Criterion released in WCAG version: 2.0

Official description of the success criterion

If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content.

What to do?

Provide suggestions for correcting input errors.

Why is it important?

Assists users in successfully completing forms and inputs.

Common pitfalls

Not providing known suggestions for correcting errors. Remember to check these also with a screen reader! In many cases, a suggestion might be shown to a sighted user.

How to test for it?

Fill in forms with test content - if you expect some type of content to fail, use that type of content to check for errors.

More about this criterion elsewhere