RegexLab Documentation

Master regular expressions with our comprehensive guide. Learn the fundamentals, explore common patterns, and practice with interactive examples.

What are Regular Expressions?

Regular expressions (regex) are powerful patterns used to match, search, and manipulate text. They provide a concise and flexible way to identify strings of interest, such as particular characters, words, or patterns of characters.

RegexLab helps you learn and practice regular expressions through interactive testing and guided training exercises.

How to Use RegexLab

1

Regex Playground

Use the main playground to test your regex patterns against sample text. Get real-time explanations and see detailed match information.

2

Training Mode

Practice with guided exercises that challenge you to write regex patterns for specific scenarios. Progress through different difficulty levels.

3

Documentation

Reference this documentation for common patterns, syntax explanations, and learning resources.

Basic Regex Concepts

Literal Characters

Most characters match themselves literally:

cat matches "cat"

Special Characters

Some characters have special meaning and need escaping:

\. matches literal dot
\* matches literal asterisk

Ready to practice? Head to the Training page to test your regex skills!