Limited Availability

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.

Baseline Status: This feature is currently Limited (not yet Baseline). Latest engine implementation shipped on Jul 2, 2026.

Desktop Browser Engine Support

Google Chrome

150

Supported

Mozilla Firefox

—

Unsupported

Apple Safari

—

Unsupported

Microsoft Edge

150

Supported

Mobile Browser Engine Support

Chrome Android

150

Firefox Android

—

Safari iOS

—

Specifications and References

Specification ↗ Feature XML ↗

MDN Browser Compat Data Keys:

api.ProcessingInstruction.doc_html ↗ api.ProcessingInstruction.getAttribute ↗ api.ProcessingInstruction.getAttributeNames ↗ api.ProcessingInstruction.hasAttribute ↗ api.ProcessingInstruction.hasAttributes ↗ api.ProcessingInstruction.removeAttribute ↗ api.ProcessingInstruction.setAttribute ↗ api.ProcessingInstruction.toggleAttribute ↗