macOS uninstaller apps: do you need one?

What macOS does without one

• Finder. Quit the app and drag it from Applications to the Trash, or choose File → Move to Trash, then empty the Trash. That is Apple's own method.
• Storage settings. System Settings → General → Storage → Applications lists your apps by size, with a Delete button.
• The app's own uninstaller. Apple's advice is that if an app includes one, it is the best way to remove the app with its login items and extensions. Adobe's apps, VPNs, security tools and audio drivers usually ship one.

None of these looks in your Library for what the app left there. Apple says so plainly: deleting an app does not remove the files you made with it, and it does not cancel a subscription you bought through it.

What an uninstaller app adds

An app is more than its bundle in Applications. While you used it, it wrote settings to ~/Library/Preferences, data to ~/Library/Application Support and its container, caches to ~/Library/Caches, and sometimes helpers to LaunchAgents and LaunchDaemons that start on their own. Most of those files are named after the app's bundle ID, such as com.example.appname, rather than its name. An uninstaller reads the bundle ID, and those of the app's helpers, before the app goes, searches both Library folders for them, and lists what it found with sizes so you can remove the lot together.

Doing the same without one

Get the bundle ID first, while the app is still installed:

mdls -name kMDItemCFBundleIdentifier /Applications/AppName.app

Then list everything that carries it:

find ~/Library /Library -iname "*com.example.appname*" 2>/dev/null

Check each result, move it to the Trash rather than deleting it, and remove the app last. The full steps, and what to leave alone, are in how to uninstall apps on a Mac. If the app is already gone, the leftover files after uninstalling an app goes through each place by hand.

What to check before you trust one

• It shows every file before it removes anything, with its path and size, and lets you untick one.
• It moves your files to the Trash, so an uninstall can be undone until you empty it. Root-owned files in /Library cannot go to the Trash; a good uninstaller says which those are and asks for your administrator password before removing them.
• It does not match on a name alone. A search for "Google" or "Microsoft" reaches folders shared by apps you are keeping. Matching on the bundle ID, and leaving files that belong to another installed app, is what keeps it to one app.
• It leaves shared data unticked. A chat app's group container can hold the message history and media. That should be your decision, not the default.
• It refuses Apple's own apps. Apps that macOS needs, such as Mail and Notes, cannot be removed in Finder either, and should not be removed around it.

When you do not need one

If the app is small, sandboxed and from the App Store, its leftovers are mostly its own container, and finding that by hand takes a minute. An uninstaller earns its place with apps that install helpers, with apps you try and remove often, and when you want to see the size of what an app left behind before you decide. For space rather than tidiness, start with the clean-up checklist: an unused app is rarely the largest thing on the disk.

Where the app comes in

RefreshYourMac's Uninstall an App is a macOS uninstaller built in. It reads the bundle ID of the app and of its helpers, login items and XPC services, searches both Library folders, and shows every piece with its size and kind before anything moves. Everything in your own Library goes to the Trash; only root-owned files, such as launch daemons, are deleted outright, after the password prompt. A file that names another installed app is left for that app, a group container is listed but not ticked, anything it will not touch is shown under Left alone with the reason, and Apple's own apps are refused. Its Unused Applications category lists the apps you have not opened in a while, largest first. Both are in the download edition; the Mac App Store edition does not uninstall apps.