Regex Tester
Test a regular expression against sample text and see every match highlighted, live.
Match 1: hello@example.com at index 14
Groups: $1=hello $2=example.com
Match 2: support@example.org at index 35
Groups: $1=support $2=example.org
Uses your browser's native regex engine (JavaScript flavor) — everything stays on your device.
Frequently asked questions
Which regex flavor does this use?+
JavaScript's native regex engine (the same one your browser uses) — supports capture groups, named groups, lookaheads/lookbehinds, and all the standard flags.
Why is there no 'g' checkbox?+
The tool always searches for every match so it can highlight all of them, regardless of what flags you pick — the flags shown (i, m, s, u) are the ones that actually change matching behavior.
Is my text sent anywhere?+
No — matching happens entirely in your browser using JavaScript's built-in RegExp.