Regex Tester & Debugger
Test regex patterns with real-time matching and highlighting. Everything runs locally in your browser.
What is Regex?
Regular expressions (regex) are patterns used to match character combinations in strings. They're essential for validation, searching, and text processing. Whether you're validating email addresses, extracting URLs from text, or parsing log files, regex is the tool for the job.
This regex tester shows you matches in real-time with syntax highlighting. It supports JavaScript regex syntax including all flags (global, case-insensitive, multiline, dotall). You can see all matches, capture groups, and match positions.
Unlike other online regex testers, qtoolkit.dev processes everything client-side in your browser. Your test data never leaves your machine, making it safe for testing with sensitive strings like emails, passwords, or API keys.
Common Patterns
Email: [a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,} URL: https?://[^\s]+ Phone: \d{3}-\d{3}-\d{4} Date (YYYY-MM-DD): \d{4}-\d{2}-\d{2}