Why You Can't Delete Mac System Apps

Hi this is Gary with MacMost.com. Let me tell you why you can't uninstall some of the apps that come with your Mac. 

So on your Mac if you want to uninstall an app you can do it simply by dragging the app from the Applications Folder into the Trash. You can see here how I can uninstall Pages. It ask me to confirm. I confirm with my Account Password. Now the app is in the Trash. I can empty the Trash. 

But you can't do that with all apps. For instance if I go to the Messages App and let's say I want to uninstall that, I can't drag it to the Trash. It won't let me. Furthermore, if you go into System Settings and you go to General, then Storage, and then you go down to where it says Applications, wait for it to finish calculating. Then you click the i button right next to it and then you see all your apps usually sorted by size. Now you can easily uninstall a lot of them with this interface. So, for instance, if you want to delete Pages you can select it and you've got a handy Delete Button right here. But other apps, for instance like Passwords you can see the delete button is grayed out. It's the same button but you can't actually move to the Trash in the Applications Folder. So what's going on here? Why can't you uninstall these apps?

Well, they're all apps that come with the System. Things like Mail, and Messages, and Calendar, and Contacts, and Passwords. There's a whole bunch of them that you can find you can't delete. What's the reason for this? Is it because Apple wants to force you to use their apps? Well, No, it's not that at all. You can just simply not use the apps. A lot of them have alternatives. For instance you cannot use Mail and just get your Mail through a web interface. You cannot use Password and use a third party password manager. You could not use Calendar and use some business calendar app. You're free to just ignore these apps and not use them.

So that is it because these apps are integrated into the Operating System and into other apps. Well, somewhat. Yes they are typically well integrated in and if you could delete them there would be some issues there. For instance there are some functions in Mail that rely on Contacts or associating names with email addresses. Mail would have to operate differently if you could delete the Contacts App. So there are a lot of things like that. But that is not the real reason. 

The real reason is Security. Your security actually. This is all due to something called the  Sign System Volume. Previously called the Read Only System. This is a way that Apple protects your and your Mac from malware and from malicious hackers. Apple spells this all out right in the Mac Help. So you can see here in this Support Guide you've got all this information about the Sign System Volume. 

if you find these videos valuable consider joining the more than 3000 others that support MacMost through Patreon. You get exclusive content, course discounts, and more. You can read about it at macmost.com/patreon. 

Now this started back in 2019 with macOS Catalina when the System was made Read Only. So you

couldn't alter the System. You couldn't add things into the folders there or remove them. Then it went up a level in 2021 with Big Sur when that System became cryptographically signed. So that is to prevent the System from being tampered with. So the idea is you've got the System that is exactly the System that Apple distributes. If anything changes with it, any files, any tiny bit of file a changes, then the cryptographic signature won't match anymore and your Mac knows that its System has been tampered with. 

So to understand how that works a very simple example of that is the check sum. Let's say you have a book and you counted very letter; AB1, BB2, and so on and you added them all up. You may have a big thick book but you probably only end up with, say, an eight digit number that was the addition of all those letters. If somebody tried to change anything, a word, a sentence, or even a single letter then that number would no longer match and you would know that book has been tampered with. The real way it works is way more complex than that. But that gives you the general idea that you can't change something in the System without the System knowing. 

So when Apple set this up they had to decide what comprised the System. Obviously there is the Core System but something like the Finder certainly should be part of that as well. Of course lots of other different apps including some where it makes sense to make sure those are not tampered with either. So some of the apps that we have on our Macs are actually part of the System and are in that Read Only cryptographically signed section that can't be tampered with. Other things are external to that. Third party apps and even some of Apple's apps like Pages, Numbers, and Keynote that can be downloaded and installed independently as part of the System. 

In fact if you look in the Applications Folder you can easily see if an app is part of the System or not. For instance, if I were to select Pages here and then use Command i to get info on it I can see it's location is Macintosh HD Applications. The Application Folder is not part of the System folder. But if I look at the Passwords App and get information for that I can see its location is Macintosh HD System Application. It is stored in the Applications Folder inside the System Folder and thus it is part of this Read Only secure system. You can even go to that folder. If you go to the top level computer and then you can look at your Drive, there's the Application Folder and you can see it outside of the System. But if you look in the System there's Applications and you look in there and there are all those apps that are part of the System that you can't uninstall. But if that is the case then why do they all appear in your Applications Folder together. Well that's just a simple little function of the Finder. The Finder shows you everything in your Applications Folder and your System's Applications Folder together when you look at Applications. It does this for convenience so you can find the app that you want and easily launch them, move them to the Dock, create aliases, drag and drop them, whatever you want. It would be very inconvenient if you had to go one place for some apps and another place for other apps. So the Applications Folder has this special way that you view it where you see Applications, not just there in the Applications Folder, but also in the System Applications at the same time. 

Incidentally the Read Only Signed System of Volume is exactly why it doesn't make sense anymore to reinstall the System over the current System. It is the same System. You're just reinstalling the exact same thing over what is already there. And incidentally if what you're worried about is the fact that these applications are taking up valuable storage space on your Mac, well we'll go back to that System Applications Folder here and we'll Sort By Size and see that the largest app currently is the Freeform app. It is only 87 MB. Under that there are apps that go down pretty quickly in size and a lot of them are less than 10 MB in size. So Apple has really made sure that it has kept these apps small because Apple knows you can't delete them. 

So if you've been wondering why you can't uninstall the System apps that come with your Mac, well this is why. Hope you found this useful or at least interesting. Thanks for watching.