Regex Tester
Developer ToolsTest regular expressions and inspect matches and capture groups.
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matches
Groups:
What is Regex Tester?
Regex Tester runs a regular expression against sample text and shows matches and capture groups.
How to use Regex Tester
- 1 Enter a pattern and any flags.
- 2 Paste the text to test.
- 3 Inspect the highlighted matches and groups.
Supported formats and limits
- Input: pattern and test text
- Output: matches and capture groups
- Runs in your browser
Common uses
- Test a pattern against sample text before using it.
- Inspect captured groups while building an expression.
- Debug a regular expression that is not matching.
Things to know
- JavaScript regex flavour may differ from other languages.
- Catastrophic backtracking can freeze the browser on some patterns.
Privacy and file handling
Testing happens in your browser; no data is uploaded.
Frequently asked questions
Which regex flavour is used?
The tool uses the JavaScript regular expression engine, which matches browser behaviour.
Which regular expression flavour does the tester use?
It uses your browser's JavaScript regular expression engine.
Can I see capture groups?
Yes. Matches and capture groups are highlighted as you edit.
Is my test data uploaded?
No. Everything runs locally in your browser.
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