HTML Guides for complimentary

The WAI-ARIA specification defines a strict set of valid role values, and "complimentary" is not among them. This is a straightforward typo — "complimentary" (meaning “expressing praise or given free of charge”) versus "complementary" (meaning “serving to complete or enhance something”). When a browser or assistive technology encounters an unrecognized role value, it ignores it. This means screen reader users lose the semantic meaning that the <aside> element would normally convey, making it harder for them to understand the page structure and navigate effectively.

The <aside> element already carries an implicit ARIA role of complementary as defined by the HTML specification. This means assistive technologies automatically treat <aside> as complementary content without any explicit role attribute. Adding role="complementary" to an <aside> is redundant. The simplest and best fix is to remove the misspelled role attribute and let the element’s native semantics do the work.

If you have a specific reason to explicitly set the role — for example, when overriding it with a different valid role — make sure the value is spelled correctly and is an appropriate role for the element.

Examples

❌ Incorrect: misspelled role value

<aside role="complimentary">
  <h2>Related Articles</h2>
  <ul>
    <li><a href="/guide-one">Getting started guide</a></li>
    <li><a href="/guide-two">Advanced techniques</a></li>
  </ul>
</aside>

The value "complimentary" is not a valid ARIA role. Assistive technologies will ignore it, and the element loses its semantic meaning.

✅ Correct: remove the redundant role

<aside>
  <h2>Related Articles</h2>
  <ul>
    <li><a href="/guide-one">Getting started guide</a></li>
    <li><a href="/guide-two">Advanced techniques</a></li>
  </ul>
</aside>

The <aside> element already implies role="complementary", so no explicit role is needed. This is the recommended approach.

✅ Correct: explicitly set the properly spelled role

<aside role="complementary">
  <h2>Related Articles</h2>
  <ul>
    <li><a href="/guide-one">Getting started guide</a></li>
    <li><a href="/guide-two">Advanced techniques</a></li>
  </ul>
</aside>

This is valid but redundant. It may be appropriate in rare cases where you want to be explicit for clarity or to work around edge cases with certain assistive technologies.

Quick reference for similar typos

Always double-check role values against the WAI-ARIA role definitions to ensure they are valid. When an HTML element already provides the semantics you need, prefer using the element without an explicit role — this follows the first rule of ARIA: “If you can use a native HTML element with the semantics and behavior you require, do so.”