HTML processing instructions #907

This GitHub issue is for collecting web developer signals for HTML processing instructions.

An HTML processing instruction is text enclosed by <? and >, which marks a target for further processing. They may appear anywhere in a document. They are ignored like comments when they're not recognized for a specific purpose.

Browser support

• Chrome 150 (Jun 30, 2026)
• Chrome Android 150 (Jun 30, 2026)
• Edge 150 (Jul 2, 2026)
• Firefox: not supported
• Firefox for Android: not supported
• Safari: not supported
• Safari on iOS: not supported

Give us feedback

If you're pressed for time, but you want this feature to be available in all browsers, please give this issue a thumbs up 👍 reaction.

However, a much better guide for us is to know how you'd use this feature, and what you're having to do in the meantime. This helps us judge the priority versus other features.

Copy the template below in a comment, and add the details that matter to you.

## What I want to do with this feature

<!-- Add your specific use-cases, even if they seem obvious to you. -->

## What I'm having to do in the meantime

<!--
Are you having to use another feature instead, a polyfill, or is it blocking you completely?
Why are the alternatives worse than using this feature?
-->

All comments are expected to adhere to the Code of Conduct.

Learn more

You can learn more about this feature here:

• web features explorer
• webstatus.dev
• Specification