Flags supported
Enter JavaScript flags such as g, i, and m.
DEVELOPER & DATA TOOLS
Regex Tester
Test a pattern against real text and inspect every matching value and index.
FreeNo sign-upProcessed in your browser
Test a regular expression
Enter a pattern and flags to list matches and their positions.
When do you test regex?
Use a regular expression to validate or find values with a repeatable pattern, such as email addresses, codes, or keywords.
Clear errors
Invalid patterns show an error instead of running.
DEVELOPER & DATA TOOL
Regular expression tester for patterns, flags, and sample text
Enter a pattern, choose flags, and test it against sample text to inspect matches before using it in code.
When to use it
Use it to check validation rules, find repeated text, or test a pattern before adding it to an application.
How to use it
- Open the tool and add the file, text, or value you want to work with.
- Use the available controls to review, edit, convert, or test the result.
- Check the result, then save, copy, or export it when needed.
Frequently asked questions
Which regex flavor does this use?
The tester uses the browser JavaScript regular expression engine. Syntax from other languages can behave differently.
Can I test flags?
Yes. Add the flags supported by the tool to see how they change matching behavior.