I use Clean My Mac now for several years and never thought about its usefullness. But today I found out it does empty my user cache, including the one for Mixbus11. This caused this program to rescan each time I have used Clean My Mac all my plugins (several hundreds), which takes each time a lot of time. It took me several runs to find out how to disable this specific cache cleaning. I changed a setting and now it does not clean ANY user cache. So my first question: is this OK? Secondly this behaviour lead me to dive a bit deeper into the usefullness of Clean My Mac and I find various opinions on the Internet, ranging from “total crap” to “very useful”. Many people mention that the Mac on its own is very capable of maintaining its own system. And for example OnyX Titanium does a similar job, but for free. So I wonder what the opinion of this Tidbit community is.
You can pick which things that Clean my Mac does, and if clearing the cache is not solving a problem, then skip that. What do you use it for and what do you expect it to help with on your system?
I have used it mostly to check which updates are available (it doesn’t see them all, but enough for me to see if anything needs an important update).
I run it now and then completely, so all the options. But because of this cache problem I did disable cleaning the user cache and it solved this particular problem with my application, but my question was if it is OK to disable cleaning for all user caches.
I have home consultant friends who call it “the golden goose.” They are sure to get several calls a year from people who have used it and hosed their system in one way or another.
I use it occasionally with settings i arrived at years ago and have not changed since. But definitely not all options.
Well the general opinion seems to be on the Internet that MacOS itself is very well capable of maintaining a “clean” Mac and in particular cleaning the user cache can make the computer even slower, because the affected apps need to fill again the cache. This was exactly the case with Mixbus11! So I will use from now on CleanMyMac optionally. One good feature seems to be Space Lens, showing you the size of all your folders and files. Also the check for malware seems usefull.
The features I value most are removing unused localisation languages, universal binary pruning, removing xcode junk (notorious!), old app updates.
I agree that clearing cache too frequently will cause it to need to be rebuilt which may be slower. But then we’re in the weeds because some apps have slow cache lookup etc
All to say, it depends, it’s a very personal thing.
The features of Clean My Mac I use most often are those for completely uninstalling apps and cleaning. up leftovers. I never just allow a batch process to proceed without checking the list of actions and specific files that it will clean.
i have only recently used it and am surprised at its usefulness. My particular need (in desperation) was to free up storage space on a Macbook Air. This works well with no obvious issues. But the other features, mentioned above, are also handy.
I believe MacKeeper had a very poor reputation for bogging machines down and causing problems, but I thought Clean My Mac was OK (although I’ve never used either).
I never understood those leftovers and still don’t. I have many leftovers, some big in size, but mostly small in size. I’m not sure if I can savely remove ALL leftovers. Once I did and got somehow problems with passwords or logins (I don’t exactly remember).
As long as you know what the “leftovers” are and are sure that they belong to applications that either no longer need them or that you no longer use, deleting them should be OK.
The problem I have with third-party “uninstallers” to removing “leftovers” is that they’re guessing about what files “belong” to an application. They have to guess because there’s no list of files generated by the application noting what files they wrote. I’ve seen and heard of too many instances where they have broken macOS or applications – sometimes to the point of having to re-install.
The same goes for “optimization” utilities. At best, they remove caches - which can reduce space but make applications run slower until the cache is re-populated. At worst, they can also break your Mac.
You run them at your own risk. And I wouldn’t run any of these utilities that a) don’t tell you ahead of time what they’re going to do, b) give you a chance to review and stop before executing the actions, and c) provide extensive logging of what they did so that you can check if something goes unexpectedly wrong.
Thank you for your information about leftovers. Clean My Mac tells me to which application they belong and I can review them before deleting. But as said most of these leftovers are small, only a few Kb in size, so I just let them sit untouched. I just deleted the biggest one (500+ Mb), but I knew I could savely delete that one. Still don’t know what leftovers are and why they are generated by applications.
Matt, I’m curious if you tried other Xcode-specific cleanup tools, and if so whether you find Clean My Mac better? I use DevCleaner, and find it very useful (Xcode–so piggy!), but always interested in improvements if they’re out there.
I’ve not tried any others. If it ain’t broke…
Edit: Actually, I have tried Mole and I didn’t read the options properly and approved deletion of my Simulators. Then I had to redownload them (they are huge, my connection is slow). Always read the small print 
I use Cocktail on the regular. Cocktail - A perfect mixture for macOS and yes its on our benefits page: TidBITS Member Benefits - TidBITS
Thanks for mentioning this app. Seems quite capable. maybe a replacement for CleanMyMac.
I recently got CleanMyMac, and it does seem to be a bit over-the-top (it constantly wants me to quit Safari because it uses a lot of memory).
For many years, to accomplish the complete removal of software I not longer want, I’ve use AppZapper https://appzapper.com/>, which works quite well (gets all the ancillary files). Unfortunately, it’s an Intel application, so its days may be numbered.
I rely on MacOS to do maintenance. If I need more then I use OnyX, Disk Utility and DriveDx mainly for diagnostics.
I just had a look at that page. I´m a bit surprised to find Nisus there. I thought it´s dead by now…