Regex Tester
Write a pattern, set flags like gimsu, and see matches highlighted as you type. Capture groups appear in a results table so you can debug extractors, validators, and search-replace workflows using your browser’s native RegExp engine.
Runs entirely in your browser. Your data never leaves this device.
- Live match highlighting
- Flags: g, i, m, s, u, and more
- Capture group table
- Browser RegExp engine
- Private — text stays local
How it works
- Enter a pattern and flags (e.g. gim).
- Matches highlight live in the test string.
- Inspect capture groups in the results table.
Key features
- Live match highlighting
- Flags: g, i, m, s, u, and more
- Capture group table
- Browser RegExp engine
- Private — text stays local
FAQ
Which regex engine is used?
Your browser’s JavaScript RegExp engine.
Are matches highlighted live?
Yes. Highlights update as you edit the pattern, flags, or text.
Can I use lookbehind?
If your browser supports it (modern Chromium/Firefox/Safari generally do).
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