Will deleting unused Mac and nonMac applications on my iMac speed it up?

Removing unused apps will not speed up your Mac.

And while they do take up disk space, you should not remove apps willy-nilly, especially Mac apps installed along with macOS (Safari & QuickTime being prime examples of apps you should never remove even if you don't use them.)

If it's an app you installed yourself and you want to remove it, ok, but all you will do is free up a bit of disk space.

If you have a reasonable amount of free space on your drive, deleting never-used apps won't do anything to speed up your Mac. It might reduce visual clutter, if you're sure you'll never want to run those apps again.

When a HDD or SSD gets very close to being full, performance can suffer a lot as the HDD becomes fragmented or the SSD tries to manage free space. Then, deleting or offloading files can make a difference.

If this is a 21.5-inch iMac made between 2012 and 2019, the most common cause of slowness is the slow and under-spec mechanical hard drives Apple fitted to entry-level models. Those drive as simply not keeping up with newer macOS versions.

Removing apps ot adding RAM cannot change that. The option of a faster extern drive is about the only option that does not require profession help and a risk of permanent damage from opening a sealed-case computer:

User-submitted tip: Use an external SSD as your startup disk … - Apple Community

It is only partially true that removing apps will not speed up your computer. There are some app that will install processes on startup that will run in the background whether you are using the app or not. This will consume resources and could slow your Mac down. To see what is getting installed on startup and running in the background, I recommend using EtreCheck and post the results here using the Additional Text option. You only need to do the free scan to determine what processes are running that could slow your system down.

Using EtreCheck - Apple Community

The only way unused apps might slow down your Mac is if your disk is full to the brim. If deleting them will give you back 15-20% of your disk space then things will improve. But that's an extremely unlikely scenario given the apps are likely to have a very small installation footprint.

Etrecheck is a very useful diagnostic app written by a long-time, trusted participant in these forums. There is a free version and a paid version. Start with the free version, it is all you really need to see important information about your system.

Etrecheck may report things you do not understand ... keep in mind that interpreting the information it provides depends on your level of knowledge & experience with macOS and Mac computers. If you have concerns or questions, post a copy of your Etrecheck report here and people with help you interpret it.

(Note: Etrecheck does not report any personal information.)

The creator of EtreCheck provides support on these forums and has helped many users. It is not malware and all you need is the free version to do the scan. It can be easily deleted by moving it to the trash. I would never recommend any cleaner apps and that is not what this is. It is only for diagnostic and will not remove any files or create Malware popups that plague many of the cleaner apps. The program is very useful in determining what processes are running when you boot your computer, which could be a reason for slow performance. Post the results here using the Additional Text option when posting to get suggestions on what could be causing any slow downs. The report does not contain any personal information.

Hi GPsFriend, strictly that, and that alone...No....not having many apps running at one time....possibly....

I* don't know what exact year and model number+specs of your iMac, just that it's a 21.5 inch iMac, running MacOS 13.4 which is Big Sur or Sonoma, so I'll assume it's pretty recent and new-ish...it's probably an m1 or M2 iMac (Apple Silicon) so it's not upgradeable at ALL, after you buy it.... not by the User, that being you, or by an AASP (apple authorized service provider) or Apple Store with Genius Bar... as it's probably a built to order product, you could have upgraded it before you bought it, but now that you have bought it. no...

John B

Hello again GPsFriend, not much, I’ve used it once, but I know it’s helpful, safe and trusted/reliable, it will not mess up your Mac or make more problems on it when used, it’ll show you where there might be a problem by generating a report… which can be used to find said problem… I’d trust it over Apps that claim to “clean your Mac” or “fix your Mac from junk”or even antivirus apps… which are bad and trouble…

John B

Anybody can claim anything about any app.

Thanks, MartinR,

I've downloaded and am strongly leaning. But pages like this: https://sites.google.com/site/howtotellifyourmacishacked/is-etrecheck-malware

make me skittish.

If I open it and then run Malwarebytes what will happen?

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Etrecheck reveals data about a Mac. I suppose some people will consider that malware simple because it does reveal the inner workings of a Mac.

I guess you better stay away from Doctors, surgeons, loan officers, car dealerships, tax specialists and every other instance when you have to give certain details somebody says you shouldn't ever.

There comes a time you have to trust somebody and if you came here looking for help, I'd think this is one of those times.

Etrecheck is a perfectly safe & useful utility. Malwarebytes will not detect anything wrong or nefarious about Etrecheck ... because Etrecheck is not malware. It simply generates a report about your Mac for you to review and you can save the report if you want to.

There is a known cyber-stalker who dislikes the author of Etrecheck. That person has posted negative reviews & comments at various times about both the software and the author. None of it is true. But once posted somewhere on the internet, it never goes away and it resurfaces periodically. That's probably what you found on Google.

I share your obvious concerns about security & privacy. And I use both utilities, and have done so for many years. Never a problem