Tools · Text · Regex tester
Regex tester
Live regex matching, entirely in your browser.
Runs fully in your browser. Nothing is uploaded.
Your file is ready.
Try a different file, or try again.
How it works
Type a pattern.
Paste sample text.
See matches highlighted live.
Frequently asked questions
No. Your pattern and text are matched entirely in your browser.
JavaScript's own RegExp engine, since that's what runs in your browser.
The tool detects it and stops after one second, with a clear message, instead of freezing the page. A small number of patterns can take exponentially long against certain text (called catastrophic backtracking) - this tool catches that case rather than hanging.
Not token by token. It shows exactly what matched in your own text and what each capture group caught, which is usually more useful than a generic syntax explanation.
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