For the most part, it’s easy to install and uninstall applications in Mac OS X. Most applications can be installed by dragging the application icon into the Applications folder, and can later be uninstalled by dragging that same icon to the Trash. It doesn’t get much easier than that.
However, some apps also come with support files, generally placed in /Library or ~/Library (more specifically, if the developer is following Apple’s guidelines, in /Library/Application Support or ~/Library/Application Support). You’ll often find such support files if an application was installed using an installer utility, but they can also be placed there by the application itself the first time it’s run. And don’t forget preferences files, which almost every app has and which reside in /Library/Preferences or ~/Library/Preferences.
So how do you really uninstall an application, confident that you’ve rid your hard drive of everything associated with that app? If the application came with an “uninstaller”—or if its installer includes an uninstall option—use that. Otherwise, one of the easiest ways I’ve found is to use the $13 AppZapper 1.5.1 ( ) by Austin Sarner and Brian Ball. To get rid of all traces of an application, simply drag it into the AppZapper window; you’ll be presented with a list of all files AppZapper concludes are associated with that application:


In the example above, I dropped the Camino Web browser icon onto AppZapper; AppZapper showed me how much space Camino and its related files were using on my hard drive and then displayed those items: Camino itself, Camino’s folder of support files in the Application Support folder, Camino’s preferences file in ~/Library/Preferences, and Camino’s folder of cache files in ~/Library/Caches. You also see the size of each file or folder, and you can view any item in the Finder by clicking the magnifying-glass icon next to it in AppZapper’s list. (One bit of information not included here that I’d like to see is the application’s version number.)
Click the Zap button and all checked files are moved to the Trash (accompanied by a somewhat startling “zap” sound—consider yourself warned); if you want to keep a particular file or folder for any reason—for example, in case you ever decide to reinstall the application—uncheck the item before “zapping.” (You’ll notice that no documents are deleted, or even made available for deletion, by AppZapper. So there’s little chance you’ll accidentally delete personal data; the closest thing would be application preferences. Still, a similar utility, CleanApp, can archive “uninstalled” files just in case you make a mistake and need to reinstall later; I’d like to see such functionality added to AppZapper.)
I should add a word of warning here—one that applies to any “uninstall” utility: Be careful with applications that share resources and/or are part of larger software packages, as you may accidentally delete files that are needed by other applications. For example, support files for one application in a suite of apps may also be used by other applications in that suite. AppZapper seems to handle this fairly well by erring on the safe side: I dragged individual apps from a number of popular software packages onto AppZapper, and didn’t find any instances of shared resources being deleted. However, that doesn’t mean it can’t happen. And it’s also worth nothing that a consequence of being safe here is that, when zapping such applications, AppZapper may not always delete everything associated with the app. So in such cases I recommend using the software package’s own uninstall/remove feature or utility.
To avoid zapping important applications and their support files, you can drag them into AppZapper’s “safe” list. There are also options to keep all of OS X’s default applications safe, as well as to keep currently-running applications from being removed.
If you’d like to clean house, so to speak, AppZapper’s ZapGenie feature lists all applications on your hard drive—at least, by default, all those in the /Applications directory on your boot volume—along with each application’s location, its version number, and how long it’s been since you last used it. (The last bit of information is based on the application’s “Last opened” date, which can be viewed via the Finder’s Get Info window.) You can sort this list by name or last used, and you can search the list by application name. To delete an app, check its box and click the Go button; the result will be just as if you’d dragged that application onto AppZapper. If you check multiple apps, clicking Go will give you a longer list of all the selected apps and their support files, separated by app.

(I mentioned that, by default, the ZapGenie feature searches only /Applications; however, you can manually add—via the preferences [gear icon] button—other locations, such as ~/Applications or a folder of applications on another hard drive.)
The process of preparing the ZapGenie list can take a few minutes, which makes sense considering how many applications are on the typical hard drive. However, when you process an application using ZapGenie, AppZapper returns to its main window; clicking the ZapGenie button to use the feature again causes AppZapper to re -search for applications, instead of using the previous list. So if you’re planning on “zapping” multiple applications using ZapGenie, you should do so all at once.
AppZapper also makes it easy to “uninstall” system add-ons: System Preferences panes, widgets, plugins (input managers, Internet plugins, QuickTime components, and iTunes visualizers), and screen savers. Just click the Action menu in the main AppZapper window and choose the item you want to remove; you’ll be shown a list of files relating to that item that you can choose to zap.


However, this feature also revealed a bug in AppZapper: When I used it to delete TiVo Desktop (a preference pane with several support files) from my system, AppZapper wanted to delete the entire /Library/StartupItems folder—a folder used by other software packages and one that should not be deleted—instead of the TiVoDesktop folder inside of that folder. Which goes to show that even with good “uninstall” utilities, you need to pay attention to what they’re deleting.
Finally, you can view AppZapper’s searchable log, which lists all files you’ve ever removed via the utility along with the date of removal and the original path to each item.
Not everyone will need a utility like AppZapper, but if you’ve downloaded (and kept) a lot of virtual crud over the years, or if you frequently try out (and then promptly forget) apps, AppZapper makes it easy to quickly rid your computer of unwanted bits.
AppZapper requires Mac OS X 10.4 (Tiger) and is a Universal application.