Regex Tester
Test and debug regular expressions with real-time matching and syntax highlighting.
//
Enter text above to see highlighted matches
What are Regular Expressions?
Regular expressions (regex) are patterns used to match character combinations in strings. They're powerful tools for text searching, validation, and manipulation used in virtually every programming language.
Regex Flags Explained
- •g (Global): Find all matches rather than stopping after the first
- •i (Case Insensitive): Makes the pattern case-insensitive
- •m (Multiline): ^ and $ match start/end of each line
- •s (Dot All): Allows . to match newline characters
- •u (Unicode): Enables full Unicode support
Common Regex Patterns
\dAny digit (0-9)\wWord character\sWhitespace.Any character*0 or more+1 or more?0 or 1^Start of string$End of string[abc]Character setTips for Writing Regex
- •Start simple and build complexity gradually
- •Use non-capturing groups
(?:...)when you don't need the match - •Use
*?or+?for lazy matching - •Escape special characters with backslash
- •Test with edge cases and unexpected input
100% Private
All regex testing happens locally in your browser using JavaScript's built-in RegExp engine. Your patterns and test strings never leave your device.