Regex Tester
Type a pattern and some test text to see every match highlighted with its capture groups, flags (g i m s u y) and a replacement preview. The engine is your browser's own JavaScript RegExp, so results match what your code will do.
How to use
Live matches, capture groups and a replace preview for JavaScript regex. Your data is processed only inside this browser tab.
FAQ
Which regex engine does this use?
Your browser's JavaScript RegExp — the same one your Node or frontend code uses, quirks included.
Can a bad pattern freeze the page?
Deeply nested quantifiers on long input can be slow, so input length is capped. Keep test data under a few hundred KB.
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