🔍 Developer Tool

Regex Tester & Debugger

Test regular expressions in real-time with match highlighting, capture groups, and a comprehensive cheat sheet. Supports JavaScript regex syntax.

g (global)
m (multiline)
i (case-insensitive)
s (dotAll)
u (unicode)
0
Matches
0
Groups
0ms
Exec Time

Common Regex Patterns

Regular Expressions Cheat Sheet

Character Classes

Pattern Description Example
. Any character except newline a.c matches "abc"
\d Any digit (0-9) \d{3} matches "123"
\w Word character (a-z, A-Z, 0-9, _) \w+ matches "hello_world"
\s Whitespace \s+ matches spaces/tabs
[abc] Character set [aeiou] matches vowels
[^abc] Negated set [^0-9] matches non-digits

Quantifiers

Pattern Description
* Zero or more
+ One or more
? Zero or one
{n} Exactly n times
{n,m} Between n and m times

FAQ

Which regex flavor does this tool use?

This tool uses JavaScript's native RegExp engine. Most patterns are compatible with other flavors (Python, Java, PHP), but some features like lookbehind assertions have limited browser support.