Accessibility Checklist: Error Prevention
Bobby Bailey
How to Prevent Errors and Improve Usability
Error prevention is essential for accessibility, ensuring that people can complete tasks without unnecessary mistakes. Well-designed forms and interactions guide people through processes smoothly. Use this checklist to minimize errors and improve accessibility.
10-Point Accessible Error Prevention Checklist
Number one: Provide clear instructions before form submission
Explain the required format for inputs (e.g., "Enter phone number as (123) 456-7890"). Include examples where helpful.
Number two: Use input constraints to prevent errors
Apply type="email", type="number", or type="date" to enforce proper input formats. Use dropdowns or radio buttons instead of free-text entry where possible.
Number three: Validate data in real-time
Show errors before form submission to prevent frustration. Allow corrections without forcing a page reload.
Number four: Mark required fields clearly
Use the required attribute and provide clear visual indicators. Do not rely solely on color to indicate required fields.
Number five: Ensure error messages are descriptive
Instead of "Invalid input," explain what needs to be corrected (e.g., "Password must be at least 8 characters"). Error messages should appear next to the affected field.
Number six: Allow people to confirm before submitting critical actions
Require confirmation before deleting an account, making a purchase, or submitting irreversible changes. Provide a "Cancel" option alongside confirmation buttons.
Number seven: Enable undo for destructive actions
Allow people to reverse deletions or major actions when possible. Example: Show an "Undo" button after deleting an item.
Number eight: Use accessible error indicators
Pair error messages with icons or text labels, not just color. Example: Show an "X" icon along with "This field is required."
Number nine: Prevent session timeouts from causing data loss
Warn people before a session expires and allow them to extend it. Auto-save form data whenever possible.
Number ten: Test with real users and assistive technologies
Use screen readers to verify that error messages are properly announced. Ensure all error-handling features work with keyboard-only navigation.