Regex Tester
Test a regular expression live — matches highlighted, groups listed.
Highlighted
Contact ada@smpl.lol or linus@kernel.org today.
2 matches.
- #1 @ 8: ada@smpl.lol$1=ada $2=smpl
- #2 @ 24: linus@kernel.org$1=linus $2=kernel
Uses your browser's native JavaScript regex engine, so the syntax and flags are exactly those of RegExp. With the g flag every match is found and highlighted; without it, only the first. Capture groups are listed as $1, $2… and named groups by name.
How to test a regex
Type your pattern, toggle the flags you need, and paste a test string. Matches are highlighted in place and listed below with their groups. With the g flag on, every match is found; without it, only the first.
Reading the results
The highlight shows what matched; the list shows where each match starts and what each capture group captured. An empty group is shown as a small symbol so you can tell it apart from a missing one.
Questions
Which regex flavor is this?
JavaScript's native RegExp. Patterns, escapes, and flags (g, i, m, s, u, y) behave exactly as they would in your code, so what you test here is what you'll get at runtime.
Does it show capture groups?
Yes. Each match lists its numbered groups as $1, $2, and so on, and any named groups by name, alongside the position where the match started — so you can confirm your capturing logic at a glance.