1. Computer Skills
  2. OS X

How to Install and Properly Remove Apps


There are thousands of applications available for your Mac, but when it comes to installing them there seems to be a different method for every single one. With the exception of those in the Mac App Store, software on OS X is typically available in one of four formats: an app file (.app), a package (.pkg), a disc image (.dmg), or a ZIP file (.zip) with one of these inside.

In this tutorial, I’ll show you how to install and fully remove any app. We’ll go over doing the latter quickly with a third-party app (AppCleaner) and the more complicated approach of browsing for an app’s files.

Installing Apps

The package (.pkg) icon.
The package (.pkg) icon.

In this section, I’ll cover installing applications from all available consumer sources. I will not be discussing how to compile an app because it is much more advanced and requires developer skills.

DMG With App File

“DMG” is an acronym for “disc image”. If you’ve not been acquainted, a disc image is a virtual disc — a CD or DVD that resides on your computer’s hard drive. When you open one, you are basically inserting a disc into your computer and loading the install files. These can either be in the form of a package (see below) or a .app file. To install the latter, simply drag it to your Applications folder.

A disc image with an app file and Applications shortcut in it.
A disc image with an app file and Applications shortcut in it.

Some developers include an alias (a linked folder) so you can quickly drag this file to the proper location without needing the sidebar in Finder. Most of the time this is a direct link to your Applications folder and it helps you install the app quickly, rather than searching for where to put it. Some people don’t understand where an app is supposed to be installed, so they just drop it on their desktop. Worse, others think it’s okay to run the app of the disc image. The problem with that approach is everything disappears when you restart since the image must be remounted.


Installing Java with a package.
Installing Java with a package.

“PKG” is an acronym for “package”. It’s similar to a Windows executable file, but you can’t also use it to run the app itself. (.App files are not traditionally be used to install an app on a Mac. Dropbox is one of the few developers who uses this method, only because its app requires account linking and other special information.) Here’s how to install a package:

  1. Double-click it or select it and use the keyboard shortcut CMD + O.
  2. Every app has its own conditions and special information for initiating an install, so be sure to read things thoroughly as you proceed through the installation.
  3. After clicking Continue, you may be asked which disc you wish to install the app or service on. Beware that installing it on an external hard drive has not fared well for many. There’s a big disconnect between the drives at times and if you forget to plug in the external one, things may become corrupted. If it’s a separate partition, things should work okay, but there’s still a risk of problems.
  4. The last screen may ask whether or not you want to launch the app, view its readme (a bit of documentation), or maybe add it to the dock upon quitting the installer. Occasionally you’ll encounter one that asks you to restart. There’s always a warning at the beginning of the install, though, so as long as you read things this shouldn’t come as a surprise.

.ZIP Archives With an App File

A ZIP archive with install files inside.
A ZIP archive with install files inside.

Sometimes — very seldom — a developer will compress his app inside an archive. There are various formats of digital archives, but ZIP is the most common one and it’s unlikely you’ll see others when installing a consumer app. Why compress an app? So it doesn’t take as long to download it. There’s not a significant different in size when you’re installing something 20–80 MB, but ZIP compression can help a lot when it’s a few hundred megabytes.

To install an app from a ZIP archive, double-click it and then follow one of the other sections, depending on which format the installer/app is.

From Mac App Store

Installing content from the Mac App Store.
Installing content from the Mac App Store.

For reference, installing an app hosted on the Mac App Store takes a few quick steps:

  1. Launch Mac App Store.
  2. Locate the app you wish to purchase or download.
  3. Click the blue price tag (may simply say “Free”) for the app and select either Install or Buy App, depending on the option which you are presented with.
  4. Enter your account password to validate your identity.
  5. Check Launchpad for the download progress. Alternatively, check the Purchases tab of the Mac App Store for this information.

Finding Installed Apps

My Applications folder.
My Applications folder.

Almost all apps will be installed in the /Applications folder of your hard drive. (Some exceptions include the aforementioned Java, which is a plugin that resides in /Library/Internet/Plug-ins.) You can locate an app either by using Launchpad, searching with Spotlight, or navigating to the Applications directory in Finder. If it’s in a different directory, you will have to search for it with Spotlight since every app differs.

Uninstalling Apps

Tip: AppCleaner and the other methods mentioned below do not always work. With apps like Microsoft Office, the developer provides an uninstall script on its website. These typically open in Terminal and require the administrator's password to proceed. It's worth visiting the developer's website before uninstalling an app to check if there's a special method it is to be done.

Now, what most consider to be the hard part. People think that uninstalling an app is difficult, but it’s actually more tedious than anything. There are some great third-party apps for quick uninstalling and I’m going to talk about one of them, but first let’s discuss the basics of an app installation.

The contents of the Preferences folder; some app settings (.plist files) are selected.
The contents of the Preferences folder; some app settings (.plist files) are selected.

OS X stores several types of data for its apps. Preferences are the most popular, and they are usually located in /Users/[Username]/Library/Preferences. Sometimes things are in /Library/Preferences, but that’s usually only if the app has global settings for all users. Preferences files store things like window location, but not game saves and other sensitive files. They are typically under the name format "com.[company name].[product name].plist”. Sometimes it will start with .org, but things usually stay along that path. An example would be fr.handbrake.HandBrake.plist.

The Application Support folder with Mozilla selected.
The Application Support folder with Mozilla selected.

Another place you can find app files is /Users/[Username]/Library/Application Support. You need to look around for your app in here since they’re not always organized by title. Some developers prefer to use the company name as the folder, so keep on the lookout for that. Application support files can be anything from game saves to app helpers (services) to logs to temporary files. Every app uses them differently.

There are other areas that you can find app-related files, but other than your Documents folder, it’s hard to find them due to the various ways developers set up apps to handle things. It’s best to stick to the above files rather than poking around, because there are many horror stories of people deleting system files thinking they belonged to a specific app.

Delete Files Manually

Securely deleting files.
Securely deleting files.

If you really like doing things manually, there’s a method that should remove most of an app’s files. You can, of course, drag the app to the trash and live with the false belief that it is gone forever, or you can delete it using Launchpad with the same thought. However, there are still leftovers.

  1. Move the .app from /Applications to the trash.
  2. Head to either your Application Support or Preferences folder and start looking for the app’s related data.
  3. While you’re at it, take a look at what’s in these folders and compare it with the apps you have installed. Eliminate the superfluous.
  4. Also move the app’s files to the trash, but triple-check that they are not related to the system and cannot harm the computer if removed.
  5. Empty your trash. You can even do so securely by right-clicking the trash, hold command, and selecting Securely Empty Trash.

Use AppCleaner

Completely removing Firefox with AppCleaner, third-party software.
Completely removing Firefox with AppCleaner, third-party software.

The easiest way to remove an app is by using AppCleaner, a free third-party utility developed by FreeMacSoft. I’ve used it for years and have never had a problem removing apps. Here’s how to uninstall something using it:

  1. Locate the app you wish to remove. Alternatively, you can skip this step and use AppCleaner’s built-in app finder.
  2. Open AppCleaner.
  3. Drag the .app to the AppCleaner dock icon or main window.
  4. The app will automatically locate preferences and app support files, bringing them into the interface for quick removal.
  5. Always read over the files list, no matter how long. AppCleaner is great, but it can still make a mistake.
  6. Once confident all is well, click Delete to move everything to the trash.
  7. Empty or securely empty the trash.

You’ve done it! Firefox is finally gone.

How Will You Go About It?

I've discussed the various ways of installing apps on your Mac, from ZIP files containing apps to packages and Mac App Store purchases. I then guided you through the removal process if the apps you chose were not to your liking. There are definitely other ways to do things, but they are either much more advanced (installing from source code) or incredibly outdated (installing legacy software from OS 9 and older). What method will you or do you use for these tasks?

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