Write and test JavaScript regular expressions without leaving the browser. Enter a pattern, optional flags (g, i, m, s, u) and sample text to see every match with capture groups highlighted in the results. Ideal for form validation, log parsing, refactors and interview prep.
🔒 Your file is processed locally in your browser whenever supported. This tool runs entirely on your device — nothing you type or upload is sent to a server, logged, or stored.
JavaScript (ECMAScript) regular expressions, the same engine your browser uses. Lookbehind and named groups depend on browser support but are widely available in modern browsers.
Check escaping (\d not d for digits), whether you need the g flag for multiple matches, and whether whitespace or case sensitivity matters. The error panel flags syntax problems.
Many patterns transfer, but flavours differ (lookbehind, word boundaries, flags). Treat this as a JS tester and verify language-specific syntax in your target runtime's docs.
| Platform | Supported | Offline | Local | Server | Network |
|---|---|---|---|---|---|
| WEB | Yes | Yes | Yes | No | Not required |
| PWA | Yes | Yes | Yes | No | Not required |
| ANDROID | Yes | Yes | Yes | No | Not required |
| IOS | Yes | Yes | Yes | No | Not required |
Compare two texts line by line and see what changed.
Check whether text is valid JSON and see the parsed type.
Check email address syntax with clear pass/fail detail.
Generate version-4 UUIDs locally using cryptographically secure randomness.
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