Question 1

Which regex flavor does the Regex Tester use?

Accepted Answer

It uses native JavaScript regular expressions, so patterns match exactly how they will run in the browser or Node.js.

Question 2

Is my pattern or text sent anywhere?

Accepted Answer

No. All matching runs in your browser — nothing is uploaded.

Question 3

Is it free?

Accepted Answer

Yes, free with no ads and no account required.