Made with Lisp, The Regex Coach is a free graphical application for Windows that you can use to experiment with (Perl-compatible) regular expressions interactively. It has the following features:

  • It shows whether a regular expression matches a particular target string.
  • Can also show which parts of the target string correspond to captured register groups or arbitrary parts of the regular expression.
  • Provides a “walk” through the target string one match at a time.
  • Simulates Perl’s split and s/// (substitution) operators.
  • It tries to describe the regular expression in plain English.
  • Shows a graphical representation of the regular expression’s parse tree.
  • Step-by-step visualization of the matching process as performed by the regex engine
  • Everything happens in “real-time,” i.e., as soon as you change something in the application, all other parts are instantly updated.

Available for: Windows

Download The Regex Coach:
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What exactly are regular expressions?

Regular expressions are strings of text which describe a search pattern. Click this link to find out more about regular expressions. You will find a lot of tools (e.g., text editors, CAT tools, etc.) that support regular expressions. I did, for example, use regular expressions in the OmegaT CAT to deal with tags that OmegaT did not understand.

Regular Expressions are powerful and complicated

If you ever used a programming language (e.g., Java or C++) or a scripting language (e.g., Perl) you probably used regular expressions. These expressions are very powerful, but they can also get very complicated. If you need to find a specific word, then the expression can be relatively simple. But if, for example, you need to find an opening and corresponding closing tag in a text, then it can get extremely difficult. Please refer to the website regular-expressions.info to find examples if you are interested.

Regular Expressions are DANGEROUS!

As mentioned above, regular expressions can get very complex (or complicated), and because of that, they can be very dangerous. If you don’t have a lot of experience, you definitely need to test your regular expression before using it. And this is where The Regex Coach will be your best friend. It is one of the best tools to test your regular expressions.