Regex Tester

Test regular expressions with real-time matching and detailed explanations.

Quick Reference

. - Any character
\d - Digit
\w - Word char
\s - Whitespace
* - 0 or more
+ - 1 or more
? - 0 or 1
[abc] - Character set

Enter a Pattern

Enter a valid regular expression pattern to test it against your text.

Understanding Regular Expressions

Regular Expression Basics

  • Literal Characters: Most characters match themselves (e.g., 'a' matches 'a')
  • Special Characters: . ^ $ * + ? { } [ ] \ | ( ) have special meanings
  • Character Classes: [abc] matches any of a, b, or c
  • Quantifiers: * (0+), + (1+), ? (0-1), {n,m} (between n and m)
  • Anchors: ^ matches start of line, $ matches end of line

Common Use Cases

  • Validate email addresses, phone numbers, and other formatted data
  • Extract specific patterns from text (URLs, dates, etc.)
  • Search and replace text with pattern matching
  • Parse and validate user input in forms
  • Clean and format data by matching unwanted patterns