When a form validation error occurs, the user is informed of where the error is, and what caused it, using text.
On this page:
This ensures that the form validation error is available to people who cannot see, distinguish colours, or understand icons and other visual cues.
Clear error messages help everyone to input and interact with content correctly. It is important to provide inclusive error messages that users of assistive technology can perceive. Keep in mind that not everyone sees visual cues, such as colour or icons. And people with cognitive impairments may have difficulty in understanding how to correct errors.
See the W3C’s detailed explanation of this guideline with techniques and examples.
For example, when a form is submitted:
a list of all fields needing correction could be added in above the form;
that list could be announced to screen reader users, either by:
form inputs that are in error are identified both visually (using than colour alone) and in code (using
aria-invalid for example).
<label for="national-insurance-number"> National Insurance number </label> <span id="national-insurance-number-hint"> It’s on your National Insurance card, benefit letter, payslip or P60. For example, ‘QQ 12 34 56 C’. </span> <input id="national-insurance-number" name="national-insurance-number" type="text" aria-describedby="national-insurance-number-hint national-insurance-number-error" /> <span id="national-insurance-number-error"> <span class="visually-hidden">Error:</span> Enter a National Insurance number in the correct format </span>