Regex Tester — Browser Developer Tool

Developer

Regex Tester is a browser-based developer tool that checks matches between a regular expression and test text.

Regex Tester

Runs in this browserInput is processed only in this browser. It is not sent to or stored on a server.

Results use the browser RegExp engine and can differ from server runtimes or database regex engines.

First line: /pattern/flags, then test text

Match result

Next actions

Regex Escape String Escape and Unescape

What is it

Regex Tester lets you paste code or strings and inspect the result immediately. It is useful for debugging, validation, and encoding tasks without server storage.

matches = text.matchAll(new RegExp(pattern, flags))

How to use

1Paste the input.
2Choose a mode if available.
3Read and copy the result.

Reference

Regex Tester — Browser Developer Tool Reference
Input	Result
sample	checks matches between a regular expression and test text

Sources & standards

MDN Web Docs: Client-side web APIs - MDN Web Docs
ECMAScript Language Specification - Ecma International

FAQ

Is Regex Tester input sent to a server?

No. This tool runs in your browser and does not send input to a server.

Can I use Regex Tester with sensitive values?

It runs in the browser, but avoid pasting tokens or passwords on shared devices or during screen sharing.