How to uninstall an app

The best Mac software is self-contained, leaving few traces when you trash its application from your Applications or other folder.

Sometimes its design is more complex, requiring installation of System Preference panes, of faceless services that are controlled by hidden Mac OS X internals like launchd. Considerate developers will then provide a proper uninstaller utility to close those components down and remove them safely, without your having to rummage around system folders and doing the job yourself.

Unfortunately not all applications are as considerate. Some have become notorious for leaving behind detritus that swallows hard disk space, or even worse blocks access to Flash content, for instance.

When you think that removing an application requires no more than trashing its main file, you should check that there is no more to do. Be most suspicious of applications that try to clean your Mac up, protect it from security or other threats, or enhance its function. These may well involve more than meets the eye, with additional components that need clearing away to complete uninstallation.

The worst software seems to go out of its way to remain, like a stain on your clothes, and can even render OS X unstable. Whilst convenient shareware removal tools make a good job of cleaning up after regular applications, they may not track down those residuals. In those cases you will need to locate and remove components manually before you have claimed back both disk space and stability. Use these ordered steps to achieve this.

Consider removing old version data

1. Open the app and clear out old versions. If the app uses the new convention to save versions as document backups, those could occupy a lot of disk space. Use the Revert to… command in its File menu to browse and remove old versions, as much as you can. If you do not do this before removing the app, those versions could become orphaned: see this article for further details. Note that this does not remove Time Machine backups, only local versions.

For App Store apps only

1. Move the app to the Trash. App Store apps have to be relatively self-contained, so this should clear most of it away in one simple step.

2. Remove its container data. Open the Library folder of your Home Folder (~/Library) and locate the Containers folder. Inside that you should find a folder named something like com.vendor.application for the app. This contains files, or links to files, for its preferences and other data. Drag that to the Trash.

3. Hide it in the App Store app (optional). Do this in Purchases. You can always unhide it later through Manage your account.

Try the obvious

1. Try the uninstaller. Your first check when wanting to uninstall any software is to locate its latest installation file(s) and check to see if there is an uninstaller supplied. Many good products that consist of more than a single application folder or file now come bundled with their own uninstaller tool that should know exactly what they need to remove. If you cannot find the installation file(s), check the vendor’s website, including its support pages.

2. Check documentation. If there is no installer apparent in the installation file, check through the documentation and/or its online help, including any last-minute ‘readme’ files. Even if they do not detail removal, they are likely to explain any more complex installation processes, or give useful clues, which can help you through the reverse. If you cannot find documentation, Control-click the application icon and Show Package Contents to look for them.

3. Check Installer listings. Software that has been installed by the bundled Installer comes with a manifest. Mount the disk image file and double-click the installation package to start it in Installer. Use the File > Show Files menu command to reveal a full listing of all the different files installed by the package. As these lists may be very long, and cannot be saved or copied, type System, or Library in the search field at the top to narrow the listing as you need.

4. Shareware tools. iTrash is one of several utilities that attempt to identify all files associated with given installed software. Drag and drop the application that you wish to remove to its opening window. It then detects associated files such as settings stored in preference lists, temporary cache storage, and allows you to remove them in one fell swoop. However these tools are not perfect and more complex software can slip residuals past.

Manual labour

1. Clean preferences. Almost all applications, and other software, store their settings in one or more property list (.plist) files in a Library/Preferences folder. Although these normally take up little space, they can cause problems in the future, as later releases of that product can choke on old files, and they can confuse licence setting. Files are often named by the reversed domain of their vendor, such as com.apple.application.plist. These are usually stored in the Library folder in your Home folder (~/Library).

2. Clean application support. The next most common location for software to tuck files away is in a Library/Application Support folder. If it was installed for all users, this is most likely to be in the top-level /Library folder, although additional files may also appear in the Library folder inside your Home folder (~/Library). These can include templates and any other support material, so can consume large amounts of disk space. Unlike preferences, there are no helpful naming conventions.

3. Clear caches. Less commonly, applications can store temporary data in a Library/Caches folder. This is more likely to appear in the Library folder in your Home folder, but as with Preferences and Application Support, you should check both that and the top-level Library folder for the sake of completeness. Software that can tuck away large amounts of temporary data, such as browsers and image tools, can silently swallow hundreds of megabytes that would otherwise be lost space.

4. Check System Preference panes. More complex applications may also need to install their own pane for System Preferences, which appears in the Other section of their listing. These are located in the PreferencePanes folders, either in the top-level Library or that in your Home folder. If the pane is used to control a faceless service, for instance, you may need to open it first, turn the service off, then remove the pane from its folder, or you could leave problems behind.

5. Remove services. Background services can also appear in the list of Login Items, accessed through the Accounts pane in System Preferences. Although their names are not always particularly helpful, check this listing when performing complex manual uninstallation. If you identify a component here that needs to be removed, select it and click on the – button. As it is run during startup, you will need to restart to render the item completely inactive.

6. Remove online documentation. Help files and online documentation can be quite tough to track down, but may consist of many megabytes of web, help, or Acrobat documents. Standard locations are inside the application itself, in which case it will be removed when you trash the application, in Application Support folders, and in Library/Documentation folders, typically in the top-level Library folder when applications have been accessible to all users. Ensure that you have checked uninstallation instructions before trashing documentation.

7. Remove receipts (optional). If the application has been installed using the bundled Installer utility, it will normally have left behind information files in the /Library/Receipts folder, and its boms sub-folder. If you are desperate to remove every trace of an installation, you can trash those files, but this is not normally done as these may be used by system features such as for repairing permissions. Irregularities in the Receipts folder can prevent such functions from completing properly.

Final checks

1. Search for residuals. Even when you have performed a meticulously complete manual uninstallation, there may still be some remaining traces of software. Use Spotlight’s search of file names, accessible in the Finder’s File > Find command or the Spotlight menu icon, to look for files whose name contains the application or its vendor. This is not a complete search, as it excludes hidden and system folders, but is worth running before your final checks.

2. Use Lingon X 2 to remove agents and daemons. Faceless background services are normally subject to a system launch controller, launchd, and should be disabled from its property lists. This is most readily accomplished using Lingon: start the app up, and browse its grouped listings of installed agents and daemons, again identified using reverse names like com.apple.agent. Select any entries to be disabled and uncheck the Enabled box, then save the change.

3. Check completion. Once everything relating to the software has been disabled and removed, restart your Mac and check that there are no remaining background services or processes emanating from hidden components. You may still see reports of errors in the logs, browsed using Console, and orphaned processes may remain in the listing of all processes shown by Activity Monitor. If you find any remains, locate them in other /Library or even /System/Library folders.

Based on a Masterclass, which was originally published in MacUser volume 26 issue 9, 2010.