Regex Tester

What is Regex Tester?

The Regex Tester is a free online tool that lets you write, test, and debug regular expressions against sample text in real time, with matches highlighted instantly as you type. Regular expressions are one of the most powerful tools in a developer's toolkit — used for validating email addresses, phone numbers, and passwords, extracting data from text, parsing log files, and performing complex search-and-replace operations. However, regex syntax is notoriously difficult to write correctly without immediate feedback. This tool shows you exactly which parts of your test text match your pattern, supports all JavaScript regex flags including global, case-insensitive, and multiline, and helps you iterate quickly until your pattern works exactly as intended. No installation or setup required — just paste your pattern and test string and see results instantly.

Why Use DevBench Regex Tester?

DevBench Regex Tester runs entirely in your browser — your data never leaves your device. No sign-up, no limits, no watermarks, completely free forever.

How to Use Regex Tester

1. Enter your regular expression pattern
2. Enter test text to match against
3. Select regex flags (global, case-insensitive, multiline)
4. View matches highlighted in real-time
5. Test and debug regex patterns instantly

Examples

• Test email validation: ^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$
• Match phone numbers: \d{3}-\d{3}-\d{4}
• Extract URLs from text: https?://[^\s]+
• Validate passwords: ^(?=.*[A-Z])(?=.*[0-9]).{8,}$
• Match dates: \d{4}-\d{2}-\d{2}

Use Cases

• Testing email validation patterns
• Debugging regex for form validation
• Testing URL extraction patterns
• Validating phone number formats
• Testing password strength regex
• Debugging text parsing patterns
• Testing data extraction regex
• Validating input formats
• Testing search and replace patterns
• Debugging log file parsing

Frequently Asked Questions