Updated Sept. 2, 2020: Updated to clear up some info about Image2Icon and adding another way to set custom icons. Thanks to Twitter user @snusmumric who helped us
If you want to add a little custom flair to your Mac, you may look at custom icons for your Mac’s applications. While you can no longer do this with the stock apps that come on Macs running 10.12 “Sierra” or newer (things like Safari, Finder, Notes, etc.) you can still do this with your 3rd party apps like Chrome, Steam, Microsoft Office, etc.
This will require 3 overall steps. First, getting the picture you want to be your custom icon (I’m going to presume you’ve done that already). Next, converting the picture to the ICNS file type, which is the filetype Mac uses for setting custom icons. Third, you’ll need set the custom icon on the app in question; here we’ll show you 2 ways to do this.
Converting to ICNS
As stated earlier, I’m presuming you have the picture file you want for your custom icon. Now you need to convert it to the ICNS file type so that your application can use it in Finder, the dock, etc. To do this, I recommend downloading the free application Image2Icon from the Mac App Store. While it has some paid features, such as pre-made folder icons and templates, turning app icons into standard image files, converting pictures into the Window icons file type, and a few other things. For this tutorial though, the free version should be just fine.
Once you’ve installed it, the app is fairly straightforward. Drag your picture into the “Create” tab, and it will begin converting into into a ICNS file, which is a pretty quick process. Once you’ve done this, You can set a few things such as background removal, rotating the icon, and a few other things. Now you can change the icon of your app of choice.
Setting the New Icon
Now that you’ve got your new icon, you can either use Image2Icon to set it or you can do it manually.
Using Image2Icon: With your custom icon still in place in Image2Icon, drag the actual application from Finder onto the custom icon generated in Image2Icon. You will then see a blue wheel spin around the custom icon, followed by the Application in Finder suddenly change to your new custom icon. That’s it! You’re all done.
Setting it manually with an ICNS file:
Some applications you may have trouble setting the icon through Image2Icon. Not to worry, there is still a way to do it. As before, have Image2Icon create your new .icns file, then hit the “Export” button in the bottom right hand corner, and select “ICNS” in the menu that appears. Now you’ll be prompted to save your new icon to a location that’s easily accessible such as your Desktop or Documents.
Now that we have the .icns file, we can add it as the new icon for the app in question. Go to Finder and open the Applications folder. Scroll until you find the application that you are changing, then right-click/control-click and select “Get Info”. A new window will open up on the left hand side of your Mac’s screen with more information about the app in question. There will be a little picture of the icon in the top left hand corner of that window. Drag the .icns file you created onto that little icon, and you should see the mouse icon change to a green “+” symbol. You can now let go of the .icns file and see it replace the old icon. Now you can go back to the Applications folder, and see your new icon be used, though sometimes it may take launching the app for you to finally see the change.
Setting it manually with a picture file:
If you really don’t want to download another app, you actually can do this without Image2Icon. Go ahead and find the image, a png or jpg should be fine, and try to find one whose proportions are 512 x 512 px.
Once you have the image you want, open it in the Preview app, the built in PDF and picture-viewing app on Mac. Now, you’ll want to select the whole thing by hitting the CMD and “A” key at the same time, or going up to the menubar and selecting “Edit”, then “Select All” in the dropdown menu. Either way, you’ll now have your image bordered by 8 blue dots and a dotted line. Now you’ll need to copy the image, which you can do by either hitting CMD and “C” on the keyboard, or go to the “Edit” menu in the menu bar, and selecting “Copy” in the dropdown.
With your image copied, go to the Applications folder, right click on the applications whose icon you want to set, and select “Get Info” from the menu that pops up. This will open the Application info menu, and in it you’ll see the app’s current icon in the top left corner. Click on it so that it’s highlight blue, then hit CMD and “V” on the keyboard to paste the new icon. You should now see the new icon in the top left corner, and it should appear as the new icon in your Finder and Dock within a few seconds or upon next opening the app.
Restoring the Old Icons
If you ever decide you need to go back to the original icon, you can do so, but it depends how you set the icon in the first place (or you can always reinstall the app from the vendor, though that might be overkill).
If you used Image2Icon to automatically set the custom icon, then you can use the restore function. Just go back to Image2Icon’s main screen, and at the very bottom hit the “Restore” tab. Then drag your app into the the circle, let it go, and then Image2Icon will restore its original icon.
If, however, you manually set the icon, you may not be able to use Image2Icon’s functionality. Instead, go to the app in Finder, right click on it, and select “Get Info” again. Now click on the icon in the top left hand corner, and hit the “delete” key on your keyboard. This will delete your custom icon and revert it back to the last icon in use.
If, for some reason, the app reverts to a blank image icon, you may need to grab an image of the original icon from the internet, convert it to .icns, and then change the icon the manual way (see above). Overall, though, it’s not too difficult a process.
If you prefer, you can always check it out in video form below: