Regex tester
Test a regular expression against sample text and see every match and group.
Text to test against
0 characters · stays in your browser
Settings
Enter some text to continue.
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About Regex tester
- What does Regex tester do?
- Test a regular expression against sample text and see every match and group.
- Who is it for?
- Writers checking length against a limit, researchers cleaning up lists, developers encoding values, and anyone comparing two versions of a document.
- Is it free?
- Yes. Regex tester is free with no account, no watermark on your output, no daily cap and no trial period. Because it runs on your own device it costs us nothing to run, which is why there is no catch.
- Is it safe to use with confidential files?
- Yes, and not because we promise to behave. Regex tester never sends your file anywhere — the work happens in your browser. There is no upload, so there is no copy of your document in our systems at any point.
How to use it
- 1
Enter your text
Paste it into the box above. Nothing is sent as you type.
- 2
Check the settings
Sensible defaults are already chosen. Most people never need to change them.
- 3
Run it
The progress bar shows real progress, not a decorative animation. Everything happens on your device.
- 4
Preview the result
Look at the output before you download. If it is not right, adjust a setting and run it again — nothing has been saved anywhere.
- 5
Download
Save the file. Closing this tab discards it from memory, so download anything you want to keep.