Regex Tester
Test regular expressions live with match highlighting, groups and replace
\d \w \sdigit, word char, whitespace^ $ \bstart, end, word boundary* + ? {n,m}0+, 1+, optional, range(…) (?:…) (?<name>…)capture, non-capturing, named[abc] [^abc] [a-z]any of, none of, rangea|b (?=…) (?!…)alternation, lookaheadWhy people choose us
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Frequently asked questions
Which regex flavour does this use?⌄
The JavaScript (ECMAScript) engine built into your browser. Most syntax is shared with PCRE, but a few things differ — e.g. no possessive quantifiers, and lookbehind requires a modern browser. Patterns you test here behave exactly as they will in JS code.
Is my text sent anywhere?⌄
No. Matching, grouping and replacement all run locally with your browser’s native RegExp, so your patterns and test data never leave the page. It works offline too.
Can a regex freeze the page?⌄
A pathological pattern (catastrophic backtracking) can be slow, but only in your own tab. We advance past zero-width matches and cap results at 10,000 to keep the UI responsive. Prefer specific patterns over nested quantifiers like (a+)+ on long input.