Regex Tester & Debugger Online
Free online regex tester with real-time match highlighting, group extraction, and a quick reference cheat sheet.
Test String
Regex Cheat Sheet
. — any char
\d — digit [0-9]
\w — word char
\s — whitespace
\D — not digit
\W — not word
\S — not space
\b — word boundary
^ — start
$ — end
* — 0 or more
+ — 1 or more
? — 0 or 1
{n} — exactly n
{n,m} — n to m
[abc] — char class
[^abc] — negated
(abc) — group
a|b — alternation
(?:abc) — non-capture
💡 What
Regex Tester
- Tests regular expressions against text in real-time, highlighting all matches and extracting capture groups.
📖 How
Steps
- Enter regex pattern and flags
- Type test string — matches highlight live
- Capture groups shown below
🎯 When
Use cases
- Debugging complex regex patterns
- Extracting data from text
- Learning regex with the cheat sheet
FAQ
Which regex flavor?▾
JavaScript regex (ECMAScript). Lookbehind is supported in modern browsers.