Regex Tester & Debugger
Live highlighting, flags, groups & shareable links — runs entirely in your browser.
Privacy-first • Local
Flags
Supports
$&, $1, and named groups via $<name>.About this regex tester
This regular expression tester highlights matches in real time, lists indices, and lets you inspect numbered and named capture groups. It supports i g m s u flags, safe max-scan limits, quick presets, and shareable URLs for easy collaboration.
How to use
- Type a pattern (no surrounding
/slashes) and toggle flags. - Paste test text; matches are highlighted instantly.
- Click a match to jump in the preview and view its groups.
- Use Replace with
$&,$1, or$<name>for named groups. - “Escape” menu helps turn selections into safe regex or JS string literals.
Tips
- Use Max scan to keep huge inputs snappy (avoid catastrophic matches).
mmakes^/$work per line;smakes.match newlines.- Named groups:
(?<name>...), referenced via$<name>in replacement.
Is it free?
Yes. No account required and no usage limits.
Do you store my data?
No. Everything runs locally. Drafts/settings may be saved in your device’s localStorage.
Which flags work?
The JavaScript flags i, g, m, s and u are supported.
Last updated: October 20, 2025