Regex Tester

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Regex Tester
Build, test and debug regular expressions live in your browser — instant match highlighting, capture groups, substitution preview, a plain-English explanation and ready-to-paste code for 15+ languages.

Runs entirely in your browser using the native JavaScript regex engine — nothing is uploaded. The generated code lets you take the same pattern to 15+ languages.

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The global (g) flag is recommended to replace every match.

Live testing uses the JavaScript engine. Some flavors (Go, Rust) do not support look-arounds or back-references.

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