Welcome to RegExLib.com, the Internet's first Regular Expression Library. Currently we
have indexed 4970 expressions from
2296 contributors around the world.
We hope you'll find this site useful and come back whenever you
need help writing an expression,
you're looking for an expression for a particular task, or are ready to
contribute new expressions you’ve just figured out. Thanks!
Expresso is useful for learning how to use regular expressions and for developing and debugging regular expressions prior to incorporating them into C# or Visual Basic code.
- Build complex regular expressions by selecting components from a palette
- Test expressions against real or sample input data
- Display all matches in a tree structure, showing captured groups, and all captures within a group
- Build replacement strings and test the match and replace functionality
- Highlight matched text in the input data
- Test automatically for syntax errors
- Generate Visual Basic or C# code
- Save and restore data in a project file
- Maintain and expand a library of frequently used regular expressions