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Accessibility
How does a form help with incorrect input?
A form helps with incorrect input by making a concrete correction suggestion: instead of "Invalid input", it says "Please enter the date in DD.MM.YYYY format, for example 03.05.1980". Anyone who only gets the error reported, with no way to the solution, tries things at random or gives up. WCAG criterion 3.3.3 requires correction suggestions whenever the website knows the correct format.
From error notice to solution
Between "Invalid input" and "Please enter a four-digit postal code, for example 1010" lies the difference between frustration and completion. People with learning difficulties, concentration problems, or little experience with forms regularly struggle with messages that only state a problem instead of helping. This also applies to every other visitor: every guessing attempt costs time and patience — and with every failed attempt, the likelihood rises that the order or inquiry gets abandoned. The criterion requires suggestions wherever the website knows the correct format: date formats, phone numbers, postal codes, selection values. An exception applies where the suggestion would endanger security or purpose — a sign-in form, of course, never reveals which password would have been correct.
How the audit service checks the error suggestions
Whether an error text really helps the visitor is a question of wording — a machine can check that a message exists, but can barely judge whether it says "check input" or "please enter a four-digit postal code". Our automated measurement uses the submission attempt from criterion 3.3.1 to establish whether errors are detected and reported at the field at all. The report marks the quality of the suggestions as a manual check point. At the Gold Standard level, a human deliberately fills in your forms incorrectly and judges every message: does it name the field, explain the problem, and show the way to a correct input.
- Deliberately fill in your forms incorrectly — wrong date format, letters in the phone number — and read every message critically.
- Write a concrete example of the correct input into every error message, such as "for example 03.05.1980".
- Include format requirements in the field label itself, so the error doesn't arise in the first place.
- Keep sign-in fields deliberately restrained — for passwords, a reference to the rules helps, never to the correct value.
FAQ
What's a good correction suggestion in a form?
A good correction suggestion names the field, explains the problem, and shows the correct format with an example: "Date of birth: please enter in DD.MM.YYYY format, for example 03.05.1980". The visitor can then fix the error on the first attempt. Messages like "Invalid input" only satisfy criterion 3.3.3 if the website itself doesn't know the correct format.
Does the error-suggestions criterion also apply to password fields?
The criterion allows an exception where the suggestion would endanger security. A sign-in form therefore never reveals which password would have been correct, or whether a username exists. What's permitted and helpful is a reference to the rules, such as the required minimum length when setting a new password — it helps the legitimate user without giving anything away to attackers.
How are correction suggestions checked?
Whether an error message really helps is a matter of wording and needs human judgment. Our automated measurement uses a submission attempt to establish whether errors are detected and reported at the field; the report marks the content quality as a manual check point. At the Gold Standard level, an auditor deliberately fills in the forms incorrectly and assesses every single message.