Bad value “” for attribute “aria-describedby” on element “a”: An IDREFS value must contain at least one non-whitespace character.

The aria-describedby attribute cannot be an empty string. It must contain at least one valid ID reference, or be removed entirely.

The aria-describedby attribute accepts a space-separated list of id values that point to elements providing a description for the current element. When a screen reader encounters an element with aria-describedby, it reads the text content of each referenced element as additional context.

An empty string ("") is not a valid IDREF value. The W3C validator expects at least one non-whitespace character. This often happens when a template engine or JavaScript outputs an empty variable into the attribute, or when a CMS generates the attribute without a corresponding value.

If no description exists, remove the attribute altogether. An absent aria-describedby is perfectly fine — it simply means the element has no supplementary description. Assistive technologies handle missing attributes gracefully, but an empty one can cause unpredictable behavior.

Examples

Invalid: empty aria-describedby

<a href="/settings" aria-describedby="">Account settings</a>

Fixed: attribute removed

<a href="/settings">Account settings</a>

Fixed: attribute references a valid ID

<a href="/settings" aria-describedby="settings-note">Account settings</a>
<p id="settings-note">Opens your profile and notification preferences.</p>

Learn more:

MDN Reference

MDN: aria-describedby

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MDN Reference

MDN: The Anchor element

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WHATWG Spec

WHATWG: WAI-ARIA

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