I want to start by saying that this is almost a perfect tool. As a programmer, I'm very impressed by this tool. It's a very convenient, intuitive, and beautiful regex editor. It's so easy to test the perfomance of capture groups and such. This tool is even able to handle the idiosyncracies of various programming environments. For example, a regex that works in Java might not work in PHP. This app takes that into account. Really useful.So what's the problem? There's no way to save an expression (or the sample text for testing it). There is not even a way to open new tabs. If you want to start playing with a new expression, you have to erase the old. It's a shocking oversight for a developer that is clearly very talented.

I love Patterns. Drop in some real samples I want to match against, as well as any false positives (things that are matching that I don’t want to match). Type in some fake ones as well if desired. Then build up the regex, keeping the handy cheatsheet up as necessary. I like the iteration it allows me.Only things missing IMO are: 1 - ability to save a workspace, my #1 desire. I’d love to save both regexes and the samples I test it against, for later refinement or sharing. 2 - would like it to keep a scratchpad, a history of iterations. Would make it even more freeing to experiment, go back and forth, and recover complicated bits after working out another section of logic. Right now, to solve both of these, I keep a text doc handy and copy out my work (patterns and example text) frequently so I have a record of work.

I was looking for a standalone macOS regex app. This happened to be on sale so I thought, what the heck. I figured it'd be nice as a backup for when the regexr website goes down.A few months later, I realize I am using Patterns all the time. It is super convenient to Control-Tab into, paste in a text fragment, and immediately copy the output. It is lightening fast even for huge find/replace operations. Copying various regex group matches saves me tons of time too. Overall I am extremely happy with the app. One minor thing would be a notebook or sidebar or something where you can save expressions. Otherwise great. Don't even wait for a sale to save a dollar or two. Just buy it. You will end up loving it.

Patterns is the best regex development/testing tool I've found -- once you find your footing it's quick to iterate with, and it's ability to copy the regex to a variety of implementations is a real time saver. Unfortunately, it doesn't offer a way to save the regexes in any way other than copy/pasting into another app. If there was either a library where (multiple versions of?) completed regexes could be stored with the testing snippets, or some sort of file export mechanism (even a yaml file) then this would be a 5 star app in my top ten Appstore apps of all time.