Regex Tester
Runs in your browser — your data is never uploaded.
Test a JavaScript regular expression against your own sample text and see every match — including its position and capture groups — updated live as you type or edit the pattern. Runs entirely in your browser.
0 characters · runs entirely in your browser
How to use Regex Tester
- 1
Enter your regex pattern and any flags (e.g. "gi").
- 2
Paste sample text into the box.
- 3
Matches update automatically as you type — no button to click.
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Frequently asked questions
What flavor of regex does this use?+
JavaScript’s native RegExp engine — the same syntax used in browser and Node.js code, including named capture groups like (?<year>\d{4}).
Do I need to include the "g" flag myself?+
No. The tester always searches for every match regardless of whether you include "g" — it’s added automatically if missing so you always see the full match list.
Is there a limit on matches?+
Results are capped at 1,000 matches per run, mainly as a safeguard against patterns that could otherwise match excessively on very large input.
Is my text uploaded anywhere?+
No. Matching runs entirely in your browser — nothing is sent to a server.