Regex JavaScript Free

Online Regex Tester

Test regular expressions with live match highlighting and flag controls. Supports JavaScript regex syntax.

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About this Regex Tester

Genbox's regex tester runs entirely in your browser — no data is sent to any server. It uses the native JavaScript RegExp engine, making it perfect for testing patterns you'll use in Node.js, browser JavaScript, or TypeScript projects.

Supported Flags

Flag Name Effect
g global Find all matches, not just the first
i ignoreCase Match regardless of letter case
m multiline ^ and $ match line boundaries
s dotAll . matches newlines
u unicode Full Unicode support

Want to learn more about regex? Read our complete regex cheat sheet.