RegEx Knife is an easy and useful tool for working with Regular Expressions.  RegEx Knife is unique in how it allows you to highlight capture groups within a Regular Expression, edit them and immediately see the results. RegEx Knife also makes it easy to experiment with regular expression substitutions.

Version 2 retains the simplicity of the original RegEx Knife, with the added advantage that it works on your iPhone as well as your iPad.

What’s New

Version 2.0.2

This version introduces Dark Mode support and resolves a number of bugs.

Ratings and Reviews

4.3 out of 5
15 Ratings

15 Ratings

Chris Pike ,

Needs a Dark Mode update

Excellent tool for fine tuning regular expressions with clear visual feedback.

The custom keyboard keys are equally clever, but turn invisible in Dark Mode. Fortunately it's usable without them.

Anna Vashka ,

Great tool

I have been using this for years and it has been so helpful and easy that I just took it for granted and never wrote a review. A great way to test and store regex.

OurBigAdventure ,

Nice and Simple

I like this app, it's simple and easy to use. It is exactly what I needed to store my regular expressions and as a bonus it allows me to also store test content to help me remember what the expression does in case the title I create isn't clear in the future.

The only issues I discovered are the list not refreshing properly when adding a new empty expression and I can't figure out what the substitution template is for. Other than those simple things this app is awesome!

App Privacy

The developer, Mark Alldritt, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

More By This Developer

You Might Also Like