How to use the Regex Tester
Fill in the fields above and the result appears straight away. Everything runs in your browser, so nothing you type is uploaded.
How it works
JavaScript RegExp
Examples
- With the default values
Match 1: “tools” at index 7 Match 2: “tool” at index 36
Limitations and assumptions
Uses JavaScript regular-expression syntax. Patterns can be computationally expensive; avoid untrusted patterns on huge text.
Frequently asked questions
What does the Regex Tester do?
Test a JavaScript regular expression against sample text and list matches.
How does the Regex Tester work?
Fill in the fields above and the result appears straight away. Everything runs in your browser, so nothing you type is uploaded.
What should I keep in mind when using the Regex Tester?
Uses JavaScript regular-expression syntax. Patterns can be computationally expensive; avoid untrusted patterns on huge text.
Can I see an example of the Regex Tester?
The pattern \btool\w* matches “tools” and “tool”.
Is the Regex Tester free to use?
Yes. It is free, needs no account and runs in your browser.