Regex Tools

Free online regular expression tester with real-time matching, pattern explanation, and code generation for JavaScript, Python, PHP, and more.

What is a Regular Expression?

A regular expression (regex or regexp) is a sequence of characters that defines a search pattern. Regular expressions are used for string matching, validation, and text processing in almost every programming language.

How to Use This Regex Tools

  1. Enter your pattern - Type your regular expression in the pattern field
  2. Set flags - Toggle flags like global (g), case-insensitive (i), or multiline (m)
  3. Add test string - Enter the text you want to test against
  4. View results - See matches highlighted in real-time
  5. Understand your regex - Read the auto-generated explanation
  6. Generate code - Get ready-to-use code in your preferred language

Features

  • Real-time regex matching with instant highlighting
  • Detailed pattern explanation and breakdown
  • Support for JavaScript regex flavor
  • Find and replace (substitution) mode
  • Capture group visualization
  • Code generator for 8 programming languages
  • Share and save regex patterns via URL
  • Common patterns library with 30+ ready-to-use expressions
  • Comprehensive regex cheat sheet

Supported Regex Flags

  • g - Global search (find all matches)
  • i - Case-insensitive matching
  • m - Multiline mode (^ and $ match line boundaries)
  • s - Dotall mode (. matches newlines)
  • u - Unicode support