Regex tester
See what a JavaScript pattern matches.
Test a JavaScript regular expression against text in the browser. Matches are listed here and the text is not uploaded.
This stays in your browser. Nothing you type or drop here is sent to a server.
How to use this calculator
- Enter the pattern and optional flags i, m, s, or u.
- Paste the text. At most 100 matches are listed.
- An invalid pattern is shown as an error, not a crash.
Questions
Regex tester: is the input uploaded?
No. The page reads and writes only in this browser. There is no account and no server round trip.
What should I check before trusting the result?
Test a JavaScript regular expression against text in the browser. Matches are listed here and the text is not uploaded.