Regex Tester
Test and debug regular expressions live — matches highlighted, no server.
Pattern
/
/
Test string
Result
Enter a pattern and test string.
How it works
1
Enter your pattern
Type a regular expression in the pattern field. Supports full JavaScript RegExp syntax including lookaheads, lookbehinds and named groups.
Type a regular expression in the pattern field. Supports full JavaScript RegExp syntax including lookaheads, lookbehinds and named groups.
2
Toggle flags
Enable global (g), case-insensitive (i), multiline (m), dotAll (s) and other flags using the checkboxes.
Enable global (g), case-insensitive (i), multiline (m), dotAll (s) and other flags using the checkboxes.
3
Test against input
Paste your test string. All matches are highlighted in real time as you type, with each match colored distinctly.
Paste your test string. All matches are highlighted in real time as you type, with each match colored distinctly.
4
Inspect capture groups
Named and numbered capture groups are listed in a table — invaluable when building complex patterns for parsing or validation.
Named and numbered capture groups are listed in a table — invaluable when building complex patterns for parsing or validation.