Syntax
<s>No longer valid</s> and <u>Underlined text</u>Examples
Outdated Information
Marking text that is no longer accurate.
<p><s>Store hours: 9am - 5pm</s> New hours: 8am - 6pm</p>Completed Checklist Items
Using s for completed or crossed-off tasks.
<ul>
<li><s>Set up project repository</s></li>
<li><s>Configure build pipeline</s></li>
<li>Write documentation</li>
</ul>Marking a Proper Name
Using u for a non-emphasis annotation, like flagging a name in a spellcheck-style context.
<p>The book was written by <u>Fyodor Dostoevsky</u> in 1866.</p>Best practices
- Use <s> for content that is genuinely outdated or no longer relevant, and <del> instead if you are specifically tracking a document edit
- Avoid <u> purely for underline styling — since links are also underlined by default, it can confuse users into thinking underlined text is clickable
- Neither element implies importance — use <strong> or <em> when that is actually the intent
- Prefer CSS text-decoration for purely stylistic underline/strikethrough with no semantic meaning
Browser compatibility
Support applies to the named feature, not every attribute or behaviour in this article. Versions refer to browsers, not operating systems.
<s>
Desktop
- Chrome
- Supported
From 1 - Firefox
- Supported
From 1 - Safari
- Supported
By 4 (possibly earlier) - Edge
- Supported
From 12 - Opera
- Supported
From 15
Mobile
- Safari on iOS
- Supported
By 3.2 (possibly earlier) - Chrome for Android
- Supported
From 18 - Firefox for Android
- Supported
From 4 - Samsung Internet
- Supported
From 1.0
MDN BCD record for this feature · MDN reference
Support history and limitations
Chrome
- From 1
Firefox
- From 1 · Before Firefox 4, this element implemented the HTMLSpanElement interface instead of the standard HTMLElement interface.
Safari
- By 4 (possibly earlier)
Edge
- From 12
Opera
- From 15
Safari on iOS
- By 3.2 (possibly earlier)
Chrome for Android
- From 18
Firefox for Android
- From 4
Samsung Internet
- From 1.0
<u>
Desktop
- Chrome
- Supported
From 1 - Firefox
- Supported
From 1 - Safari
- Supported
From 1 - Edge
- Supported
From 12 - Opera
- Supported
From 15
Mobile
- Safari on iOS
- Supported
From 1 - Chrome for Android
- Supported
From 18 - Firefox for Android
- Supported
From 4 - Samsung Internet
- Supported
From 1.0
MDN BCD record for this feature · MDN reference
Support history and limitations
Chrome
- From 1
Firefox
- From 1 · Before Firefox 4, this element implemented the HTMLSpanElement interface instead of the standard HTMLElement interface.
Safari
- From 1
Edge
- From 12
Opera
- From 15
Safari on iOS
- From 1
Chrome for Android
- From 18
Firefox for Android
- From 4
Samsung Internet
- From 1.0
MDN BCD 8.1.5 · Dataset built 2026-10-08 · Mapping reviewed 2026-10-21. These dates are not individual browser-test or claim-verification dates. Unknown means the data does not establish support.