Regex Tester

Test and debug regular expressions in real-time. All processing happens in your browser.

Regular Expression/pattern/flags

Test String

How to use the Regex Tester?

Enter your regular expression in the pattern field (without the surrounding slashes).
Paste or type the text you want to test against in the test string area.
Toggle flags (g, i, m, s, u) as needed. Results update in real-time.
Matches are highlighted and listed with their positions and capture groups.
Everything happens entirely in your browser. No data is sent to our servers.