Regex Tester
Test a regular expression against your text and see the matches highlighted live, with capture groups and a match count. Toggle the flags to change behavior. Uses JavaScript regex; runs in your browser.
Highlighted matches
FAQ
What does this regex tester do?
You enter a pattern and test text, and it highlights every match live, lists capture groups, and shows the match count. Toggle the g, i, m and s flags to change how matching behaves.
What regex flavor does it use?
JavaScript (ECMAScript) regular expressions — the same engine your browser and Node.js use. Most syntax is shared across languages, but advanced features differ, so test in your target language for edge cases.
What do the flags mean?
g finds all matches; i is case-insensitive; m makes ^ and $ match line starts/ends; s lets the dot match newlines.
Is my text or pattern sent anywhere?
No. Matching runs entirely in your browser — nothing is uploaded, logged or stored.
More tools: text diff checker, JSON formatter, and the full tools list.