Regex tester
Test JavaScript regular expressions with live matches.
This tool runs in your browser. Your files and text are not uploaded.
Loading tool…
How to use Regex tester
- Enter a pattern and flags.
- Paste test text.
- Review matches and groups, or try a replacement.
Questions
What happens with a catastrophic pattern?
Matching runs in a background worker with a one-second limit. If a pattern takes too long, it is stopped and you get a warning instead of a frozen page.
Related tools
More in Developer tools · All tools · Tool ID developers/regex-tester