Regex Tester

Test JavaScript regular expressions against your text instantly: see the match count and the index of every match.

Regular Expression Test

Pattern

Flags

Test Text

How It Works

Your pattern and flags are compiled with the JavaScript RegExp engine. Invalid patterns show the exact error message instead of failing silently.

With the g flag every match is reported with its character index. Without it, only the first match is returned.

All matching happens locally in your browser.

Frequently Asked Questions (FAQ)

Yes! Every string, payload, regex, or file is processed strictly inside your local browser tab using HTML5 and Web Crypto APIs.

Yes. Once loaded, all computations run entirely client-side without relying on external API requests.

Because processing happens on your machine, limits depend only on your system's available memory.

Disclaimer Notice

Technical Disclaimer: This Regex Tester processes source code and data strictly client-side. Always back up critical code before performing minification, formatting, or encoding operations.

Regex Tester

Regular Expression Test

Matches

Disclaimer Notice