Regex Tester
Live match highlighting and capture groups.
🔒 Processed on your device — nothing is uploaded.
About the Regex Tester
Regular expressions are powerful for finding and replacing patterns in text, but easy to get wrong. Type a pattern and flags to see every match highlighted live, inspect capture groups in a table, and preview a replacement.
When to use it
- Building validation patterns for emails, phone numbers and postcodes
- Extracting data such as prices or dates from text
- Testing find-and-replace before running it on real files
- Learning regex step by step
Tips for the best results
- Add the “g” flag to find all matches, not just the first
- Use $1, $2 in the replacement to insert capture groups
- This uses JavaScript regex syntax, which is close to most other languages
How to use the Regex Tester
- Paste your input into the Regex Tester.
- The output is generated instantly in your browser.
- Copy or download the result.
Regex Tester FAQ
Is the Regex Tester free?
Yes. The Regex Tester is completely free with no sign-up, no daily limit and no watermark.
Is it safe to use the Regex Tester with private files?
Yes. The Regex Tester runs entirely inside your web browser, so your files and text are never uploaded to any server.
Does the Regex Tester work on mobile?
Yes. It works in Chrome, Safari, Edge and Firefox on Android, iPhone, Windows and Mac.
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