WCAG Guideline 3.3.6: Error Prevention (All) Explained
Estimated read time: 6–7 minutes
Guideline 3: Understandable
The Understandable principle ensures that users can easily interact with and understand web content, especially when entering information.
Guideline 3.3: Input Assistance
Guideline 3.3 focuses on helping users avoid and correct mistakes when entering information, for all types of forms and submissions.
What Is Guideline 3.3.6 Error Prevention (All)?
"For web pages that require the user to submit information, at least one of the following is true: submissions are reversible, data is checked for input errors and the user is provided an opportunity to correct them, or a mechanism is available for reviewing, confirming, and correcting information before finalizing the submission."
Guideline 3.3.6 extends error prevention safeguards to all forms and submissions, not just legal, financial, or data modification.
- Helps users avoid mistakes in any form or submission
- Essential for all users, especially those with cognitive or learning disabilities
- Applies to all forms, inputs, and user data entry
For more, see W3C: Understanding Error Prevention (All) .
Why Does It Matter?
- All Users: Need protection from accidental errors in any form
- Screen Reader Users: Benefit from clear review and confirmation steps
- Accessibility: Reduces risk and increases user confidence
For more, see W3C’s guidance on Error Prevention (All) .
What Needs Error Prevention?
- All forms and submissions, regardless of purpose
- Provide safeguards for every user input
How to Meet Guideline 3.3.6
- Make submissions reversible (e.g., undo, cancel)
- Check for input errors and allow corrections before final submission
- Provide a review and confirmation step before finalizing
- Test all forms for error prevention safeguards
For more, see the W3C's Error Prevention (All) Techniques .
Common Mistakes to Avoid
- Submitting forms without a review or confirmation step
- Not allowing users to correct errors before finalizing
- Failing to provide a way to reverse or cancel submissions
Differences Between A, AA, and AAA for Guideline 3.3.6 in WCAG 2.2
- Level AAA: Requires error prevention for all forms and submissions.
- Level AA: Not applicable (3.3.6 is a Level AAA requirement).
- Level A: Not applicable (3.3.6 is a Level AAA requirement).
For more, see the W3C’s official documentation for 3.3.6 Error Prevention (All) .
Quick Checklist
- Submissions are reversible or can be canceled
- Input errors are checked and can be corrected
- Review and confirmation step is provided
- Tested with screen readers and accessibility tools
Summary
Guideline 3.3.6 ensures that users are protected from mistakes in all forms and submissions. Safeguards and review steps are essential for accessibility and trust.
Protection and review for all—make every form on your site safe and accessible!