A Guide to App Installation, Removal, and Security on macOS
If you’re coming to the Mac from Windows, you’re probably used to either downloading apps from the Microsoft Store, or downloading an app package from a website and running its included installer. On macOS, there are several ways apps can be installed and uninstalled, which I will give an overview of in this guide.
The good news is that whatever methods the developer has employed, the installation and uninstallation processes should seem very straightforward to you, the user. Toward the end of this guide, I will attempt to explain some of the security warnings that you may come across in your use of apps, as well as best practices to keep your Mac and the information on it secure.
Mac App Store
Similar to iOS and iPadOS, apps can be downloaded and installed from the Mac App Store. While not all developers embrace this model, all apps are reviewed by Apple before they become available, making it unlikely that you will contract malware from this source.
You can access the Mac App Store either from the Applications folder or the Apple menu. Either by searching or browsing, locate the app you want to download and click the price, or if it is free, the “Get” button in the toolbar. After authenticating with your Apple ID or Touch ID, depending on your hardware and settings, the app should be downloaded and installed on your Mac and placed in your Applications folder.
A particularly common way to install apps not distributed in the Mac App Store is to download a disk image file from a website. Open this file, saved to the Downloads folder by default, and it should mount like a volume on your desktop.
In this volume, there should be two files, the app, and something like “Applications” or “drag here to install.” Whatever this file is called, it is simply a shortcut to your Applications folder and is trying to instruct you to place the app there to install it. To do this, focus on the app and choose Edit > Copy, (or press Command-C) then open the Applications folder and choose Edit > Paste (or press Command-V). If you’re not logged in as an administrator, you will be prompted to authenticate before the app can be placed in this location.
Note: while it is technically possible to run apps directly from disk images, they will lack access to the full array of system resources, and thus may not work as expected.
Using the Installer app
Another way apps can be installed is with the built in Installer app on macOS. App packages that use this method of installation are denoted by the extensions “.pkg” and “.mpkg.”
Simply open this file and follow the prompts, which often involve simply clicking continue through an introduction, read me, and license agreement, then clicking the install button. If the installer shows a “Customize” button, you may want to click it to see if other files are included in the package that you can optionally exclude from the installation, so as to avoid installing unnecessary bloatware on your system. Once you click the install button, you will be prompted to authenticate.
In theory, simply moving an app to the trash and emptying the trash should remove it from your system. In practice, however, many apps deposit small files in various locations throughout your Mac. Therefore, you may want to use a dedicated uninstaller to complete this task.
Some apps include this functionality from the menu bar, preferences window, or as a separate utility. Otherwise, you can use something like AppCleaner. This free and accessible app allows you to view third-party apps in a list and offers to delete their associated support files, and can also be configured to trigger any time you move an app to the trash.
Alternatively, you can manually remove support files from the Library folders. While apps place files in various locations inside the Library folders, much of them can be found in the “Application Support” and “Preferences” folders.
To access your user Library folder, in Finder, choose Go > Go to Folder (or press Command-Shift-G) and type or copy and paste the following path. ~/library
To access the Library folder at the root of your startup disk, in Finder, choose Go > Go to Folder (or press Command-Shift-G) and type or copy and paste the following path. /library
Caution: the library folder’s contain essential files needed for macOS to function. Therefore, only delete files if you know what they are and know you don’t need them.
Some quick tips on app security
While apps can make your Mac more useful and fun, there are still some things to keep in mind whenever you allow something to run live code on your system, control your computer or handle your data.
Note: this is not a comprehensive list of security precautions, nor is it intended to advise on a specific threat or concern.
- While anti-malware products can be useful for the prevention and removal of malicious software, they are not the panacea for all computer security needs, and certainly are not a substitute for good user practices. As the field of anti-malware products and security solutions is constantly evolving, it is hard to make a general recommendation as to what is best. However, one app that I have had good experiences with is Malwarebytes.
- Only install apps you trust. If you’re not sure if a particular app is legitimate, you may want to research it to see what others say before downloading.
- It is not uncommon for malicious actors to exploit vulnerabilities in older versions of apps and the operating system. Therefore, it is a good idea to keep your software up to date. You can configure your Mac to automatically install updates to macOS and App Store apps by going to System Preferences > Software Update and making sure the “Automatically keep my Mac up to date” checkbox is selected.
- If you get an update prompt that looks unusual or spoofed, you may not want to install it immediately; you should instead go to the developer’s website to verify that an update has in fact been released.
- If you get a message when browsing the web that you need a particular piece of software, even if the software being pushed sounds like something you recognize, do not click the provided download link.
- Do not download software displayed in a web ad that purports to speed up your Mac or clear an infection. This is a very common method used to infect a Mac with Malware or potentially unwanted apps.
- Avoid websites or file sharing services that offer pirated software, as the integrity of the code cannot be verified and is easily tampered with. As a result, such repositories are a common source of malware infection.
- The first time you open an app, you may get a warning that it is in fact an app downloaded from the Internet. While this may sound obvious, only open it if you intended to download an app. If you thought you downloaded something else, like a document or movie, do not open the file. It is likely malware posing as a harmless file in order to trick you into opening it and allowing it to access and execute code on your system. This type of malware is known as a trojan.
- If you get an error that you can’t open an app because it is from an unidentified developer, and you’re confident that you trust the app, open it by focusing on it and pressing VO-Shift-M and selecting open from the contextual menu. Click open in the resulting dialog. You should only have to do this once per app.
- If an app requests to access protected data or resources on your Mac, such as your location, contacts or camera, or if you’re unexpectedly prompted to authenticate, you may want to check the app’s documentation to get a better understanding of why this information or level of access is requested in order to make an informed decision on whether or not to comply.
- Many potentially unwanted apps gain access to your web browser by installing extensions. This is currently not believed to be an issue in Safari, as Apple has illuminated support for extensions distributed outside of the Mac App Store, but third-party browsers like Google Chrome and Mozilla Firefox can be affected. Therefore, if you find that you are getting an abnormally high number of ads, or you’re searches do not go to your chosen search engine, you may want to check what extensions you have installed, and uninstall anything you no-longer need or don’t recognize. Check your browser’s documentation for specific instructions on extension management.
- Be wary of installing configuration profiles on your Mac. As the ability to create and deploy profiles was developed primarily for enterprise use, they are capable of accessing your Mac’s settings on a deep level, changing your security and privacy settings, tracking your usage, and changing your default search engine to redirect web searches. To remove a profile you’re not comfortable with, open System Preferences > Profiles, select the profile in the table, and click delete profile.
- If you believe you have contracted malware, it may be beneficial to run an anti-malware app to scan your Mac for traces of the code that could be placed in locations not immediately obvious to you.
While this at first can sound like a lot of information, once you're used to using third-party apps on your Mac, the processes of installation and removal likely will become natural to you. I also hope that the security tips help prevent future headaches associated with malware and data loss on your Mac.
If you have any questions or believe any of the information in this guide is inaccurate, sound off in the comments.
The article on this page has generously been submitted by a member of the AppleVis community. As AppleVis is a community-powered website, we make no guarantee, either express or implied, of the accuracy or completeness of the information.
Great guide! There's also homebrew, which I find is an excellent way of installing and maintaining both command line and GUI packages.
thanks to your recommendation, I've installed app cleaner. very accessible, and makes app uninstalling simple and fast. I have smart delete turned on, so whenever I move an app to the trash, it will automatically find related support files, in which I can safely delete them all. much simpler. overall, excellent guide!