Regex Tester

Test regular expressions

Pattern

Flags

About Regex Tester

Regex Tester is a free online tool that allows developers and programmers to test, validate, and debug regular expressions in real-time. It supports multiple regex flavors and provides instant feedback with detailed match results and explanations.

How to use Regex Tester

1Enter or paste your regular expression pattern into the Pattern field at the top of the tool
2Input the text you want to test against the pattern in the Test String field
3Select your preferred regex flavor (JavaScript, Python, PHP, etc.) from the dropdown menu
4View the results instantly as matches are highlighted and detailed information is displayed below

Frequently Asked Questions

What is a regular expression?

A regular expression is a sequence of characters that define a search pattern, commonly used for pattern matching and text validation in programming.

Which regex flavors does Regex Tester support?

Regex Tester supports multiple popular flavors including JavaScript, Python, PHP, Java, .NET, and Perl regex syntax.

Can I save my regex patterns?

Yes, you can save your patterns to your browser's local storage or copy them for use in your projects.

Is Regex Tester completely free?

Yes, Regex Tester is completely free to use with no registration required and no limitations on the number of patterns you can test.

Tips and Tricks

✓Use the provided regex cheat sheet to quickly reference common patterns like email validation, URLs, and phone numbers
✓Test edge cases and special characters to ensure your regex pattern works correctly in all scenarios
✓Utilize the explanation panel to understand how your regex is being interpreted and which parts match your test string
✓Copy working regex patterns to a personal library or documentation for reuse across multiple projects