Expressions allows to play with regular expressions*. Just type your pattern and some text to test it. All the changes are updated while you're typing text or pattern. App highlights the syntax, so the pattern is easy-to-read and modify. If you use subexpressions (groups), you can highlight them by pressing cmd+shift+] (or [ – for decreasing the highlighted group number).
If you don't remember the regex syntax, just press cmd+r or click button in the top-right. You will get the reference sheet, so you don't have to remember everything.
The user interface is very minimalistic and non-distractive. By default the color is the same as your menubar, but you can always switch to dark or light mode (see: Preferences). You can also open app in beautiful full screen mode which is perfect when you want to focus or to demonstrate regular expressions to other people.

* Expressions uses ICU regular expression standard. More information you will find here:

What's New

Version 1.3.1

- fixed bug that appeared on macOS 10.11

Ratings and Reviews

Best tool for quickly developing and testing regular expressions


The primary feature that was previously lacking was the inclusion of a quick little reference sheet, but that has been added in this release. Expressions is functionally equivalent to the other regex apps in most regards, but has a much cleaner design. For that reason, it has become my goto app for quickly developing and testing regular expressions.

Lastly, I just want to note that the developer is also very friendly and quick to respond to feedback/suggestions. 👍🏼

Very helpful learning tool

Unkle Krab

I’m just starting to learn about regular expressions, and I’m very happy to have such a well-made native app to work with.

Great, minimial regex app


Simple and effective, with tasteful design. I’ve used web-based regex tools for years, but I was really happy to find a native one. Well done!


3.3 MB
Developer Tools
Age Rating
Rated 4+
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