Regex Tester
Test a regular expression against text and see the matches.
Results appear as you type
Everything runs locally in your browser — your input never leaves this page.
About the Regex Tester
The Regex Tester lets you write a regular expression and run it against sample text to see every match immediately. It's a fast way to build and debug patterns for validation, search-and-replace, or scraping without rerunning your code over and over. Your pattern and test text are evaluated locally in the browser and never sent anywhere.
How to use
- Enter your regular expression in the pattern field.
- Paste the text you want to test against.
- Adjust any flags such as global or case-insensitive matching.
- Inspect the highlighted matches and captured groups.
Frequently asked questions
- Which regex flavor does it use?
- It uses JavaScript's built-in regular expression engine, so patterns behave the same as they would in browser and Node.js code.
- Can I see capture groups?
- Yes. The tester lists the matches it finds, which helps you confirm that your groups capture exactly what you expect.
- Will my pattern or text be stored?
- No. Everything is processed in your browser, so neither your expression nor your test data leaves your device.