How to use Regex Tester
- Start by adding the pattern and test string you want to check into Regex Tester.
- Tune the Pattern, Flags controls before you check.
- The result is computed live in your browser as you edit the input.
- Use Copy matches to keep or reuse the result.
About this tool
Regex Tester runs entirely in your browser. Regex Tester tests your regular expression against sample text in your browser, highlighting matches as you type.
Your pattern and test text stay on your device. Nothing you enter is uploaded, and it keeps working offline once the page has loaded.
Frequently asked questions
What does Regex Tester do?
Regex Tester lets you check your input right in the browser using the Pattern, Flags controls, with the result shown instantly and nothing uploaded.
Does Regex Tester cost anything?
No — Regex Tester is completely free, with no sign-up and no hidden limits.
Where is my data processed by Regex Tester?
Entirely in your browser — Regex Tester keeps your data on your own machine and sends nothing anywhere.
Which regex flavor does Regex Tester use?
Regex Tester runs your pattern with the browser's own JavaScript regex engine, live and on your device.
Does Regex Tester work on mobile?
Yes — Regex Tester is just a web page and runs on any modern browser, including phones and tablets.