Regex Tester

About Regex Tester

Build, test, and debug Regular Expressions (Regex) in real-time. Our tester provides instant feedback with live highlighting of matches, group captures, and comprehensive flag support, making complex pattern matching easier for developers of all skill levels.

How to Use

1. Enter your pattern in the 'Regular Expression' field.
2. Adjust flags like 'Global' or 'Case Insensitive' to change the search behavior.
3. Paste your sample text into the 'Test String' area.
4. Instantly see highlighted matches and review the capture groups to verify your logic.

Common Use Cases

• Validating user input patterns (emails, phone numbers, passwords) during development.
• Parsing and extracting specific data from large logs or text files.
• Learning and experimenting with advanced Regex concepts like lookaheads and backreferences.

Technical Details

Uses high-performance Rust-based regex engines via WASM to provide safe, fast, and standard regex behavior directly in your browser.

Frequently Asked Questions

Which regex flavor is supported?

We use standard modern regex engines that follow common ECMAScript patterns used in most web and backend environments.

Is it safe to test sensitive logs?

Yes. This tool is client-side only. Your test data and expressions never leave your browser, ensuring complete privacy.

100% Private & Secure

This tool runs entirely in your browser using client-side technology. Your files and data are never sent to a server, ensuring 100% privacy and speed.