Free regex tester — build and debug JavaScript-compatible regular expressions with live matches and capture groups.
Regex Tester
Live ECMAScript regex with captures, named groups, and replacement preview.
Highlighted matches will appear here.0
0
1/6
0
Was Regex Tester useful?
Your vote helps us prioritize improvements.
The QuickToolz Regex Tester lets you build, test, and debug JavaScript-compatible regular expressions interactively. Type a regex and a test string and instantly see every match, capture group, named group, and replacement preview — with full flag support (g, i, m, s, u, y).
Live match highlighting
Capture groups and named captures ((?<name>…))
Replace preview with $1, $2, $<name> references
All JavaScript flags: global, ignore case, multiline, dotAll, unicode, sticky
Match count and per-match index
Regular expressions are powerful but easy to get wrong. A live tester turns trial-and-error into iteration: tweak a pattern, see matches update instantly, and ship a regex you trust.
Everything you need, nothing you don’t. Built for speed and simplicity.
Same engine as browsers and Node.js — ECMAScript spec.
Numbered and named capture groups listed per match.
See string.replace() output live with $1, $2 references.
Everything you need, nothing you don’t. Built for speed and simplicity.
Type the pattern and pick flags (g, i, m, s, u).
Got questions? We’ve got answers. Common questions about Regex Tester.
All matching runs in your browser.
Drop the text you want to match against.
Matches highlight, capture groups list, and replace preview update instantly.