Expression Lab is a lightweight Windows application based on the .Net Framework 4.0 that allows you to test regular expression (.Net flavour) patterns with real time results displayed on your target data.

Regular Expressions, or ‘Regex/Regexp’ are patterns used to match text data as desired. Expression Lab allows you to enter your targeted data (Eg. a CSV or XML file, a product list or programming code) and develop a search pattern to describe the subset of information you require with real time results shown as colored highlights over your target data. Each match also details its index in the collection of match results to help you find the same results in your .Net code.

For more information about Regex see the following links:

Screen Shots



  • Real-time results with lightning fast UI
  • Highlight results by Match, by sub groups (parenthesized patterns) or custom groups.
  • Full list view of all matches and groups with index numbers
  • Flexible Regex options (Multiline, IgnoreCase, etc)
  • Filter out the results to show only matched or unmatched data
  • Pause and resume processing to facilitate changes with a large computational load
  • Save your project for later reference
  • Smart error handling to identify problems without stepping through your code

Features in Development

  • Color coding in the pattern editor
  • Multiple patterns and input data per project
  • Color schemes
  • Release targetting .Net Framework 2.0