Regex Tester
Test JavaScript regular expressions with flags, match positions and highlighted results.
Workspace
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How to use this tool
Enter a pattern without enclosing slashes, select flags and add sample text. Run the test to inspect matches.
What to know
Patterns run in a worker with a time limit to prevent a slow expression from freezing the page. Regex syntax follows your browser’s JavaScript engine.
Frequently asked questions
How do I use Regex Tester?
Enter a pattern without enclosing slashes, select flags and add sample text. Run the test to inspect matches.
What should I check before using the result?
Patterns run in a worker with a time limit to prevent a slow expression from freezing the page. Regex syntax follows your browser’s JavaScript engine.
Is an account required?
No. This tool is free and the calculation takes place in your browser.