Regex Tester
Test regular expressions live. Runs in your browser.
Contact ada@example.com or grace@navy.com for details.
How to use
Type a pattern and choose flags (g, i, m, s, u). Matches are highlighted in your test text as you type.
Each match lists its capture groups. Add a replacement to preview the result of a replace.
FAQ
Is my data sent anywhere?
No. This tool runs entirely in your browser. Nothing you type, paste or upload is sent to a server or stored anywhere.
Which regex flavor is this?
JavaScript (ECMAScript), the same engine your browser uses.
Why did it say my pattern took too long?
Some patterns, like (a+)+$, can take exponentially long on certain text. The tester stops after a second so your page doesn’t freeze.