Regex Tester
Build and test regular expressions against sample text, with live highlighted matches and a capture-group breakdown.
Regex Tester
Live match highlighting · capture groups · perf timer · pattern cookbook · replace · explain · flavour
(evaluation always uses JS; flavour surfaces portability warnings)
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Pattern explained
About this tool
Enter a regular expression and some sample text and watch every match highlight as you type, along with the contents of each capture group. The usual flags — global, case-insensitive, multiline and others — are all supported.
Matching uses your browser's own JavaScript regex engine, so the results reflect exactly what JavaScript code will do, and nothing is sent anywhere. It is useful for writing input-validation patterns, search-and-replace rules and log-parsing expressions.