3.3.3 Error Suggestion

What does it mean?

An error message should not only say that something is wrong, but also how to fix it, when you know the answer. "Invalid date" is less helpful than "Please enter the date as DD.MM.YYYY, for example 05.03.2025".

The exception is when a suggestion would weaken security or defeat the purpose, for example telling a user which part of the login was wrong, or giving away the answer in a test.

Who does it help?

• People with cognitive or learning disabilities
• Screen reader users, who cannot easily scan the page for clues
• Anyone who would otherwise give up after several failed attempts

Common failures

• Messages such as "Invalid input" or "Error 400" with no explanation
• A password rule is only revealed after it was broken, and the message does not say which rule
• An unknown postcode is rejected without listing the expected format

How we test it

• evidence Evidence: our scanner collects material such as screenshots, lists and measurements.

Test question: Where a correction is known, the error message suggests it (e.g. "Please enter a date as DD.MM.YYYY").

A person decides every criterion. No criterion ever passes automatically.

How to fix it

<p id="iban-error">Invalid value.</p>

<p id="iban-error">Error: the IBAN is too short. An IBAN has up to 34 characters
  and starts with the country code, for example DE or EE.</p>

The message names the problem and tells the user what a correct entry looks like.

Practical tips

• Write error messages in the same plain language as the rest of the page.

Guides and patterns on this

• Forms that everyone can completeForms are where people buy, book or give up. This guide shows how labels, required fields and error messages need to work for keyboard, screen reader and magnifier users.
• Error messages that help instead of confuseErrors as text, linked, with a fix and an error summary.

Official source

Understanding WCAG 2.2 at the W3C: 3.3.3 Error Suggestion