Regex Tester
Test regular expressions with real-time match highlighting. Includes a library of common patterns (email, URL, phone), match group extraction, and a plain-English regex explainer.
How to Use the Regex Tester
Enter your regular expression pattern in the input field, set the desired flags (global, case-insensitive, multiline, dotAll), and paste your test string below. Matches are highlighted in real time. Click any common pattern button to instantly load patterns for emails, URLs, phone numbers, IP addresses, hex colors, and dates.
What Are Regular Expressions?
Regular expressions (regex) are patterns used to match character combinations in strings. They are essential for text processing, validation, search, and data extraction. Every major programming language supports regex — JavaScript, Python, Java, Go, and more. This tester uses the native JavaScript RegExp engine, so your patterns will behave exactly as they would in browser or Node.js code. If you need to encode special characters in your patterns, our String Encoder/Decoder can help. The match details panel shows each match with its index position and named capture groups.
Common Use Cases
Validate email addresses, phone numbers, or URLs before submitting forms. Extract data from log files using capture groups. Build search-and-replace patterns for code refactoring. Test patterns for web scraping selectors. Debug regex that behaves differently than expected by inspecting each match group. Use our JSON Formatter to clean up extracted JSON data from your regex matches. Build scheduled tasks using patterns with the Cron Expression Generator. The plain-English explanation helps beginners understand what their pattern actually matches.