Mac Pranks for April Fools’ Day!

Ah, April Fools’ Day. The one day of the year when idiots like me can play pranks with a minimum of backlash. Since there are two Apple Consultants living in my house, those pranks have often taken the form of “what in the heck did you do to my Mac?!!!” In honor of this great holiday, I’m going to show you my favorites of the Mac tricks you can play on your loved (and not so loved) ones. 

Be aware that you’ll need to have physical access to your target’s computer to prank him, and in some cases, you may need his password, too. I accept no responsibility for any homicides or broken marriages that actually performing these steps may cause.

Make the Screen All Trippy

This first prank isn’t one you’ll play on a longtime Mac user, as it’s been around for a while. To do this, just hit the keyboard shortcut Control-Option-Command-8, and the computer in question will invert all of the displayed colors. It looks really strange if you’re unfamiliar with what it’s doing. 

To reverse it, hit the shortcut again. Incidentally, the setting for this is in System Preferences > Universal Access under the “Seeing” tab, and if you’re looking for something a little less dramatic to fool a savvier user, click the “Use grayscale” box there instead. 


Nonfunctional Modifier Keys

As this setting isn’t particularly well known, I’m willing to bet that you could frustrate the heck out of most folks with it. Within System Preferences > Keyboard, look for the “Modifier Keys” button under the “Keyboard” tab.

Clicking on that will let you switch up the keys shown below, or you can even assign them all to do nothing. 

::evil laughter::

Scary Error Messages Are Hilarious

Using Folder Actions, your target Mac can display any message you specify when a particular folder is opened. To get started, pick out the folder that you think would be scariest for your enemy—I mean, friend—to think something’s happened to. Then select it and hit Command-I. In the Info window that appears, type your message into the “Spotlight Comments” field.

When you’re finished composing your masterpiece of evil, close that window, go back to the folder, and right-click on it. From the contextual menu, choose Services > Folder Actions Setup.

Next you’ll see a dialog box that’s labeled Choose a Script to Attach. The one you’ll want to select is called “open - show comments in dialog.scpt.”

Click “Attach,” and then you can just close the Folder Actions Setup window that remains. Now every time someone opens that folder, your sinister message will appear. 

Note that this won’t necessarily work if you navigate to the folder in column view from Finder, so it may best be applied to a folder on the desktop, say, that is usually double-clicked on to open. To stop the message from appearing, just open the folder and click on the “Clear Comments” button shown above.

As you can see from my screen shot, it seems as if this wouldn’t fool anyone. I mean, “Open Comments”? “Clear Comments”? Those buttons alone should indicate that something’s amiss. But this is one of the few tricks I’ve played on the aforementioned “other consultant” that actually freaked him out. I guess getting a message like that just scares the bejeezus out of you and makes you not think straight, right, honey?

I’m sleeping on the couch tonight.

Make Someone’s Mac Say Bad Things

This is probably my favorite trick, but you have to feel at least a little comfortable working in the Terminal for this. It’ll be OK, though, I promise. First, you’ll go to your target machine and turn on System Preferences > Sharing > Remote Login (which you’ll want to make sure you turn off for safety’s sake when you’re done pranking your pal). Then you’ll see instructions right in that window for what we’re going to do.

The beauty of this is that you can be in another part of the building, minding your own business, and you’ll still be able to remote control the other Mac as long as you’re on the same network. Awesome.

So after you’ve turned Remote Login on (and have made note of the information in that window, as in my screen shot above), go back to your own machine. To access the other Mac, open Applications > Utilities > Terminal, type in the data you got from the other machine, and hit Return.

After doing so, it’ll probably spit out some lines of text and ask you if you’re sure you’d like to connect. Type in the word “yes,” and hit Return again. Then you’ll be asked for the password of the Mac you’re trying to connect to. I sincerely hope you know that, because if not, that’s where this falls flat for you.

After you enter the password and hit Return, you should see a command prompt. And now your mischief begins—the other Mac is ready to do your bidding! Here are some fun things you can do, hitting Return after you type each command.


say "this Mac is now being controlled by the government"

This will make the other Mac speak the text you input between the quotation marks. You can make sure the volume is up before you do this, too, by typing this in:

osascript -e 'set volume 2'

Change the number at the end to be appropriate for whatever you’re making the computer say (the range is 0–7). If Innocent Target Person is listening to music already, heck, this is a prank in itself. VOLUME AT MAX! No, wait, volume too quiet to hear!

If you wanna get fancy, you can even add a bit to the command to make it speak in any of the voices listed in Utilities > VoiceOver Utility > Speech, like this:

say -v Victoria "we are coming for you"
say -v Trinoids "your Mac will now self-destruct"
say -v Hysterical "stop that tickles"




You can use the following command to randomly open programs on the target Mac: 

open /Applications/

Replace “” with the name of whatever you want, making sure to leave the “.app” part on. If the one you want to open has spaces in the name, you’ll have to type backslashes before each space to make Terminal parse it correctly, like so:

open /Applications/Carbon\ Copy\

If that’s getting too complex, though, just stick to the programs with one-word names. 



To bring Finder windows to the front:

open /System/Library/CoreServices/

This is similar to the above, but in my mind, it’s a bit more evil and subtle. They’re doing something in Photoshop? Wait, but why does Finder keep popping up? Aaaaah! Keep entering this command over and over (press the up arrow and then hit Return to make Terminal repeat the previous command), and you’ll drive your target bonkers. 

We could also talk about remotely restarting your pal’s machine or logging him out of his user account, but even I’m not that evil. Nor do I have a powerful death wish. And as always, be careful what you type in Terminal, and make sure you’re pasting in the above commands exactly. We’ve got an understanding about that already, don’t we? Good. 

Well, those are my favorites. Now go forth, dear readers, and have a happy April Fools’ Day. Keep the numbers of a good florist and/or heart specialist on hand if you decide to try any of these, and for heaven’s sake, don’t bring my name into it. I don’t need hate mail.