How to Choose the Disk Format While Formatting an External Drive on Mac

Alvaro Bernedo

Disk Formats on MacFor Mac owners, one of the most annoying/inconvenient aspects of owning a Mac is the external drive compatibility. In many cases, we learn that the native format of external drives that work seamlessly with our Macs simply won’t work (or will just work in some limited form) with Windows PCs and other devices (like your PS3 for example).

In this post, we’ll try to clarify this situation and then we’ll show you how to erase/format any external drive on your Mac.

To start, here’s a brief explanation on the different disk formats that you can choose from when formatting an external drive on your Mac and the different pros and cons of each.

Choosing the Right Format

Mac OS Extended (Journaled)

Pros: This drive format is the perfect choice for working exclusively across Macs. It supports some of the most important features of the system, such as Versions, as well as allowing your drive to work as an OS X bootable drive. There is no size limit for the files you can transfer between Macs using this format.

Cons: This drive format can be read by Windows PCs, but you won’t be able to write files on it. This allows you to transfer files from your Mac to your PC but not the other way around.


Pros: Also known as FAT32, this format allows you to use your drive universally across Macs and PCs with no restrictions when reading or writing files on both systems. Another great plus of this format is that it is recognized by most non-computer systems, such as video game consoles (like the PlayStation 3 for example) TVs and more.

Cons: The big issue with the FAT32 format is that it doesn’t support files larger than 4 GB, so if you plan to transfer or simply copy files that are larger than that size, you are out of luck.

Cool Tip: We’ve previously written about the differences between NTFS and FAT32, and how to convert FAT32 to NTFS. You might want to check them out.


Pros: The exFAT format is perhaps the best choice among all these, but it still suffers from a few drawbacks (noted below). As for its pros, it behaves just as the FAT32 format but with one great plus: It supports file sizes larger than 4 GB, allowing you to easily move them between you Macs and PCs.

Cons: As mentioned above, since this format is relatively new, its main drawback is that most consumer electronics (including TVs, cameras, and video game systems) don’t support it. So for example, if you want to put a movie on your drive to watch on your TV, you are out of luck.

Formatting/Erasing Your USB Drive on Your Mac

Now, let’s learn how to format any external drive on your Mac using Disk Utility.

Important Note: If you have important data on your USB drive, make sure to back it up before formatting your it.

Step 1: Connect your USB drive to your Mac and make sure it shows as mounted on your system.

Mounted 1

Mounted 2

Step 2: Head to the Utilities folder within the Applications folder and open Disk Utility. Once open, you will see your USB drive on the left sidebar of Disk Utility. Click on the icon for your external USB drive (the top one as shown on the picture below) to select it.

Disk Utility 1

Then click on the Erase tab at the top of the window.

Erase Tab

Step 3: On the Format: section, select your desired format, then give your USB drive a name in the Name: field and then click the Erase… button.

Format Menu

Select Format

Optional Step: If you would prefer to erase the data on your USB drive securely to prevent any data recovery program from extracting it, click on the Security Options… button. On the Secure Erase Options panel you can use the slider to select between a Fast (regular) erase or the Most Secure one, which will rewrite over your data 7 times to ensure it is completely deleted.

Format Buttons

Secure Format

And there you go. Now you know exactly which format is the most convenient for your needs and best of all, you also know exactly how to apply it to your external drive.

Also See
#hard disk#How-to/Guides

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Alvaro Bernedo

Written By

Alvaro Bernedo

Contributor at Guiding Tech