Is this regex tester free?

Yes, completely free! No sign-up required, no usage limits, and 100% client-side processing.

Which regex flavors are supported?

This tester uses JavaScript/ECMAScript regex engine, which works in Node.js and all modern browsers.

Yes! The tool includes a replace mode where you can test find-and-replace operations with capture groups.

All JavaScript flags are supported: g (global), i (ignore case), m (multiline), s (dotall), u (unicode), and y (sticky).

100%! All processing happens client-side in your browser. Your patterns and test text never leave your device.

Name: RegEx Tester & Debugger - Test Regular Expressions Online Free
Rating: 4.8 (1893 reviews)
Author: TypeDock

Pattern & Test String

Regular Expression

Flags

GlobalCase InsensitiveMultilineDotall

Test String

Matches (0)

No matches found