Test JavaScript regular expressions with match indexes, capture groups, examples, validation, and timeout protection.

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Regex Tester & Playground is a free browser-based utility in the fas fa-code category. Test JavaScript regular expressions against sample text and inspect matches, indexes, and capture groups without installing developer software.

What Is a Regex Tester?

A regex tester lets developers verify a regular expression against representative text before adding it to an application or workflow.

• Start with small representative test cases.
• Check flags such as g, i, and m carefully.
• Add edge cases before shipping a pattern.

How to Use the Regex Tester

Enter the pattern, flags, and test text, then run the test. Built-in examples can help you start common patterns.

Execution Safety

The test runs inside a short-lived Web Worker with a time limit so an expensive expression cannot block the page indefinitely.

Frequently Asked Questions

Is Regex Tester & Playground free?

Yes. The core workflow runs in your browser without requiring a paid account.

Is my data uploaded?

The tool is designed to process its inputs locally in the browser. Avoid entering secrets unless you have reviewed your own deployment and privacy requirements.