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<acronym>

The <acronym> element was used to mark up acronyms in HTML 4.01. It allowed authors to provide the full expansion of an acronym via the title attribute. However, this element has been removed from HTML5 in favor of the more versatile <abbr> element.

This page was last updated on 2025-11-17

Deprecation Warning

This element is deprecated in HTML5. Use <abbr> instead.

The distinction between abbreviations and acronyms was considered unnecessary, as both serve the same purpose of providing expansions for shortened forms. The <abbr> element now covers all cases that <acronym> previously handled.

Syntax

<acronym title="expansion">acronym text</acronym>

The element required both opening and closing tags, with the acronym text as content.

Attributes

title - The full expansion of the acronym
Global attributes - Standard HTML 4.01 attributes like id, class, style, lang, and dir

Examples

Old HTML 4.01 Syntax (Deprecated)

<p>The <acronym title="North Atlantic Treaty Organization">NATO</acronym> was established in 1949.</p>

Modern HTML5 Equivalent

<p>The <abbr title="North Atlantic Treaty Organization">NATO</abbr> was established in 1949.</p>

Another Migration Example

<acronym title="Cascading Style Sheets">CSS</acronym>


<abbr title="Cascading Style Sheets">CSS</abbr>

Migration Guide

To update your code from <acronym> to <abbr>:

Replace all <acronym> opening tags with <abbr>
Replace all </acronym> closing tags with </abbr>
Keep the title attribute and all other attributes unchanged
Update any CSS selectors that target the acronym element

Most browsers will continue to render <acronym> correctly for backward compatibility, but using <abbr> is the correct approach for modern web development.