What does the regex match?

This regex matches HTML comments, including those spanning multiple lines. Here is the token-by-token breakdown: <!-- — Matches the literal opening HTML comment delimiter. These four characters must appear in exact sequence. The exclamation mark and hyphens are not regex metacharacters, so they need no escaping. [\s\S]*? — A character class that matches any character including newlines. \s matches any whitespace character (spaces, tabs, newlines) and \S matches any non-whitespace character. To

How do I use the Match HTML Comments regex?

Use the pattern / /g in JavaScript with RegExp or String.prototype.match(). Try it in the interactive tester above with pre-loaded test strings.

Regex to Match HTML Comments

Q: How do I use the Match HTML Comments regex?

Use the pattern / /g in JavaScript with RegExp or String.prototype.match(). Try it in the interactive tester above with pre-loaded test strings.

Match HTML comments including multi-line content with this regex pattern. Captures everything between  delimiters. Free regex tester.

Regular Expression

//g

Token Breakdown

Token	Description
<	Matches the literal character '<'
!	Matches the literal character '!'
-	Matches the literal character '-'
-	Matches the literal character '-'
[\s\S]	Character class — matches any one of: \s\S
*?	Matches the preceding element zero or more times (lazy/non-greedy)
-	Matches the literal character '-'
-	Matches the literal character '-'
>	Matches the literal character '>'

Detailed Explanation

This regex matches HTML comments, including those spanning multiple lines. Here is the token-by-token breakdown:

— Matches the literal closing HTML comment delimiter. The two hyphens followed by a greater-than sign end the comment.

The g flag enables global matching so all comments in the document are found, not just the first one. This pattern is useful for stripping comments from HTML before processing, extracting conditional comments for IE compatibility, or analyzing HTML source code. Note that nested comments are not valid in HTML, so this simple pattern handles the standard case well. For edge cases involving CDATA sections or server-side includes within comments, additional patterns may be needed.

Example Test Strings

Input	Expected
<!-- simple comment -->	Match
<!-- multi line -->	Match
<div>not a comment</div>	No Match
<!- not a comment ->	No Match
<!-- nested <!-- --> -->	Match

Try It — Interactive Tester

Regular Expression

//g

Flags

gglobalicase-insensitivemmultilinesdotAlluunicodeysticky

Test String

Match Highlighting(3 matches)

<div>not a comment</div> <!- not a comment ->  -->

Matches & Capture Groups

#1index 0

#2index 24

#3index 90

Pattern: 15 charsFlags: gMatches: 3

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Related Regex Patterns

Regex to Match HTML Tags

/<\/?([a-zA-Z][a-zA-Z0-9]*)(?:\s[^>]*)?>/g

Regex to Match HTML Attributes

/([a-zA-Z][a-zA-Z0-9-]*)\s*=\s*(?:"([^"]*)"|'([^']*)'|([^\s>]+))/g

Regex to Match Self-Closing HTML/XML Tags

/<([a-zA-Z][a-zA-Z0-9]*)\b[^>]*\/>/g

Regex to Match Multi-Line Block Comments

/\/\*[\s\S]*?\*\//g