Regex tester

Match information

Pattern explanation

Highlights the pattern's syntax and explains it token by token, and marks matches with colors right on the text. JavaScript syntax; runs in your browser.

This regex tester checks your regular expression against a test text in real time, with live matches, flags and a token-by-token explanation of the pattern.

Debug your regular expressions

Regular expressions are powerful but easy to get wrong. See live which matches your pattern produces on a test text, along with its flags and positions, plus a breakdown of what each part of the pattern means.

FAQ

What regex syntax does it use?

JavaScript's (the browser's engine). Most patterns are compatible with other languages, but some advanced constructs can vary.

What do the g, i, m, s flags mean?

g finds every match; i ignores upper/lower case; m makes ^ and $ apply per line; s makes the dot also match line breaks.

Is my text sent to a server?

No. Everything runs in your browser; neither the pattern nor the text ever leaves your device.