<aside>
Defines independent content in an HTML page.
The <aside> tag is used to define secondary or complementary content related to the main content of the page.
This content is often presented as side panels (like menus, for example 😉), informational boxes, or advertisements, but it can also include appendices like sources or definitions in an article.
This is one of the new tags introduced with HTML5!
Structure and syntax of the <aside> tag
HTML
<aside>
<!-- Complementary content -->
</aside>
Examples of usage
Defining author information
HTML
<aside>
<h3>About the author</h3>
<p>Believemy trains over 10,000 developers annually to become freelancers.</p>
</aside>
Defining related articles
HTML
<main>
<article>
<h1>React vs Next.js</h1>
<p>React and Next.js are two essential technologies in modern web development...</p>
</article>
<aside>
<h3>Related Articles</h3>
<ul>
<li><a href="https://believemy.com/r/les-nouveautes-de-nextjs-15">Learn all about NextJS 15</a></li>
<li><a href="https://believemy.com/r/les-nouveautes-de-react-19">Learn all about React 19</a></li>
</ul>
</aside>
</main>
Attributes
The <aside> tag does not have specific attributes, but it supports all global HTML attributes.
| Attribute | Description | Possible value |
|---|---|---|
id | Unique identifier to target the element. | Unique text. |
class | CSS class(es) to style the content. | Space-separated list of classes. |
style | Inline CSS styling. | CSS declarations. |
hidden | Hides the element from users. | None or hidden. |
lang | Specifies the language used in the box. | Language code (fr, en, etc.). |
Browser compatibility
The <aside> tag is compatible with all browsers (except Internet Explorer 11, as it is an HTML5 tag).
| Element | Google Chrome | Safari | Mozilla Firefox | Edge |
| <aside> | Yes | Yes | Yes | Yes |