Regex Tester

Test regular expressions with live match highlighting, capture groups, and every JavaScript flag.

Runs 100% in your browserNothing is uploaded to a serverFree forever

JSON Formatter Base64 URL Encode/Decode Timestamp Regex Tester

Pattern

Highlighted matches


          

Matches & capture groups

Run a test to see matches here.

About this regex tester

Type a pattern, toggle the flags you need, and hit Test to see every match highlighted in your test string along with each match's index and capture groups. Invalid patterns are reported instead of failing silently, and named groups are shown when you use them. Everything runs locally in your browser using the native JavaScript regex engine — nothing you paste is uploaded. For anchors, quantifiers, and how to avoid catastrophic backtracking, read the regex cheat sheet.

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