Project: rehypejs/rehype-minify

Package: hast-util-is-conditional-comment@2.0.0

  1. Dependents: 0
  2. hast utility to check if a node is a conditional comment
  1. util 145
  2. utility 141
  3. unist 132
  4. html 124
  5. hast 74
  6. hast-util 46
  7. comment 9


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hast utility to check if a node is a conditional comment.


What is this?

This package is a utility to check whether a hast node is a “conditional” comment. Conditional comments are a legacy feature that was specific to Internet Explorer. They were no longer used in IE 10.

When should I use this?

You can use this package when you’re building tools that handle old and non-standard HTML, but generally it’s recommended to remove conditional comments.


This package is ESM only. In Node.js (version 16+), install with npm:

npm install hast-util-is-conditional-comment

In Deno with esm.sh:

import {isConditionalComment} from 'https://esm.sh/hast-util-is-conditional-comment@3'

In browsers with esm.sh:

<script type="module">
  import {isConditionalComment} from 'https://esm.sh/hast-util-is-conditional-comment@3?bundle'


import {isConditionalComment} from 'hast-util-is-conditional-comment'

isConditionalComment(u({type: 'comment', value: '[if IE]>...<![endif]'})) //=> true
isConditionalComment(u({type: 'comment', value: '<![endif]'})) //=> true
isConditionalComment(u({type: 'comment', value: 'foo'})) //=> false


This package exports the identifier isConditionalComment. There is no default export.


Check if a node is a conditional comment.


Whether a node is a conditional comment (boolean).


HTML is parsed according to WHATWG HTML (the living standard), which is also followed by all browsers.

Syntax tree

The syntax tree used is hast.


This package is fully typed with TypeScript.


Projects maintained by the unified collective are compatible with maintained versions of Node.js.

When we cut a new major release, we drop support for unmaintained versions of Node. This means we try to keep the current release line, hast-util-is-conditional-comment@^3, compatible with Node.js 16.


As rehype works on HTML and improper use of HTML can open you up to a cross-site scripting (XSS) attack, use of rehype can also be unsafe. Use rehype-sanitize to make the tree safe.


See contributing.md in rehypejs/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.


MIT © Titus Wormer