METHODHow the result is produced
Practical example
/tools?/giu
Method
The JavaScript RegExp engine applies pattern and flags to the test text and lists matching ranges.
Assumptions and limits
Regex dialects differ; a browser match does not guarantee identical server behaviour.
Sources
MDN RegExp
Last reviewed: August 2026Regex Tester
Test regular expressions and flags against multiline text. Matches, groups and positions are listed, while invalid patterns receive a clear error.
Enter the required values or content, adjust the options and then review the detailed result.
FAQFrequently asked questions
What can I do with Regex Tester?
Test regular expressions and flags against multiline text. Matches, groups and positions are listed, while invalid patterns receive a clear error.
How do I use Regex Tester?
Enter the required values or content, adjust the options and then review the detailed result.
Are my data uploaded?
No. Inputs and files for this tool are processed locally in your browser.
Is this tool free?
Yes. Every feature is free and requires no registration.
Does it work on mobile?
Yes. The interface is optimized for iPhone, Android, tablets and desktop computers.