What is the Regex Tester?
Test regular expressions with live match highlighting. The Regex Tester is a free online tool that works instantly in your browser — no installation, no signup and nothing to upload. It sits alongside other Developer tools on DevNibble such as JWT Decoder, UUID Generator, Timestamp Converter.
How to use the Regex Tester
- Paste or type your input.
- The result appears instantly.
- Copy or download it.
Features
- Runs 100% in your browser — your data is never uploaded or stored.
- Free forever, with no account, no ads and no tracking.
- Copy or download your result in one click.
- Fast and responsive on desktop, tablet and mobile.
Frequently asked questions
Which regex flavour is used?
It uses the JavaScript (ECMAScript) regular-expression engine with live match highlighting.
Is my test data private?
Yes — matching runs entirely in your browser.