PlanetToolbox

Regex Tester

Test JavaScript regular expressions with flags, match indexes, capture groups, and replacement previews.

Match

Yes

Matches

Flags

Text length

Regex inputs

Test JavaScript regex patterns

PatternFlagsTest textReplacement

Regex match results

#1 at 0: Toolbox
#2 at 8: tools
#3 at 33: tool

Replacement result

utility utility help builders test utility patterns.

Notes

EnginePatterns use the browser's JavaScript RegExp engine.

LimitThe tester stops after 1,000 matches to avoid runaway patterns.

Regex tester notes

This tester uses the JavaScript RegExp engine available in the browser. Patterns for other languages can differ in syntax, flags, escaping, and lookaround support.