WCAG 2.0 · Level AAA · Understandable
3.3.6 Error Prevention (All)
Manual verification
How to validate 3.3.6 by hand
At Level AAA, check all user-submitted information for a way to reverse, check, or confirm submission before it becomes final.
Start with the extension result
Reopen the reported URL and reproduce the same state (for example, after expanding a menu or submitting a form). Use the result’s Highlight action when available, or its affected-element details and CSS selector, to find the reported content. Apply the checks below to that content and its context. If the element or state has changed, rescan and record that difference before deciding whether the finding still applies.
- Submit representative data through a workflow that saves, sends, or publishes user input.
- Check whether the user can undo the submission, review it for errors and correct it, or confirm it before completion.
- Test the safeguard with realistic mistakes, including a changed value, omitted field, and mistaken recipient where applicable.
Evidence to record
Record the data submitted, safeguard available, and whether the user can correct or confirm before final submission.
Scope and exceptions
This is Level AAA and broader than 3.3.4: it applies to all user-submitted information, not only legal, financial, or data-change actions.
Record the review outcome
- Confirmed: the recorded evidence shows the requirement is not met in the tested page state, and no applicable exception explains it.
- Not reproduced: the reported issue is absent in the current state. Record the URL, state, and affected element you checked; this does not prove other pages or states conform.
- Needs more review: evidence is incomplete, the content requires human judgment, or an exception is uncertain. Record what remains to be checked instead of treating it as a pass.