ID values must be unique

[joaooliveira]

Why is this important?

Duplicate ID errors are known to cause problems for assistive technologies when they are trying to interact with content. The screen reader will look for the first instance of the referenced ID and announce the text contents of that element, which is unhelpful if that element is unrelated to the actual field. Linked anchors which references the id that are created on and off page may not work as expected.

How can I resolve this issue?

Ensure that you only use an id attribute value once on the page. Alternatively if you need multiple ids consider using a class instead.

What topics do this checkpoint affect?

• Accessibility  (WCAG 2.1 Level A, 4.1.1)

Can you explain how this checkpoint works?

This checkpoint examines the entire HTML source code and reports if any repeating ID attribute values are found.

References

• Understanding Success Criterion 4.1.1: Parsing
• F77: Failure of Success Criterion 4.1.1 due to duplicate values of type ID
• H94: Ensuring that elements do not contain duplicate attributes | Techniques for WCAG 2.0