Regex Tester

Test and debug regular expressions

How to use

1. Type your regular expression into the pattern field.
2. Paste the text you want to test against it.
3. Matches are highlighted live as you edit the pattern or flags.
4. Adjust flags (global, case-insensitive, multiline) to fine-tune matching.

Why use this tool

• Live highlighting: See exactly what your pattern matches as you type — no guessing.
• Flag control: Toggle global, ignore-case, multiline, and other flags to test real behaviour.
• 100% private: Everything runs in your browser. Your data is never uploaded to a server, so it's safe for confidential content.

Frequently asked questions

Which regex flavour does it use?

JavaScript (ECMAScript) regular expressions, the same engine browsers and Node.js use.

Why does my pattern match nothing?

Check for unescaped special characters, a missing global flag, or anchors like ^ and $ that restrict where matches can occur.

Is my test data private?

Yes. The regex runs in your browser; your pattern and text never leave your device.

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