Free Tools / Regex Tester

Regex Tester

Test JavaScript regular expressions with live matches. Fast, private and free — everything runs in your browser.

Test regular expressions

Write your pattern and flags, paste a test string, and see every match highlighted with its index position and captured groups. Great for debugging log parsers, validators, and URL routers.

Frequently asked questions

Which regex flavor is used?

JavaScript (ECMAScript). The regex is compiled with new RegExp() using the flags you specify.

Does it show capture groups?

Yes. Named and unnamed capture groups are displayed alongside each match.