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If you need to format a disk on your Mac, there may be many reasons behind this decision, such as securely erasing all data from your Mac before selling it, creating an external drive for backups, sharing data with someone using a PC or another Mac, or using a disk pre-formatted for Windows. Fortunately, formatting a disk on a Mac is simple and easy using the built-in Disk Utility tool.
Before we delve into the details, you need to know a few important things, including which file format to choose. Read on to learn more about different file formats and how to format an external drive for your Mac.
Which file format should you use?
There are several file formats you can choose from, but the best one for you depends on how you plan to use the drive:
- APFS (Apple File System): A new file system introduced with High Sierra, which is more reliable and user-friendly. It can be encrypted and case-sensitive but is not readable or usable on a Mac that’s not running High Sierra, nor can Windows or Linux machines read or write to it. It presently only works on SSDs or flash storage.
- Mac OS Extended (Journaled) (also known as HFS +): It was the default file system until 2017 when APFS replaced it. A good choice for those who want to encrypt their drive or use case-sensitive filenames. Windows can read HFS + drives but cannot write to them.
- MS-DOS FAT (also known as FAT32): A file system that can be read and written by Mac, Linux, and Windows, so it’s a good choice for sharing drives with friends or colleagues who own PCs. However, data is limited to 4 GB or smaller, which makes it unsuitable for copying larger files like movies. It offers no security and is more prone to disk errors.
- ExFAT: Similar to FAT32, but it can store data over 4 GB. Both Windows and Mac can read disks formatted with it.
- NTFS: The standard Windows file system, which can only be read by macOS, not written. There are third-party tools that allow you to do this, but reliability can be an issue.
How to Format an External Drive for Mac
If you want to format a disk to use it with a Mac, follow these steps:
- Open Disk Utility by going to Applications > Utilities or typing “Disk Utility” in Spotlight search.
- Select the disk you want to format from the list of available drives on the left. Remember that formatting will erase all data, so back it up first.
- Click the “Erase” option from the four options in the main window.
- Choose the format you prefer, which Disk Utility will select based on the drive’s current format and the macOS version you’re using. If you want to use a different format, click the formatting options to open the drop-down window.
- Name the disk clearly so you can easily identify what’s on it.
- Click the “Security Options” button if you want to securely erase all data on the disk. Choose the level of security you prefer using the slider.
- Click “Erase” and wait while the disk is being formatted and prepared.
- Once formatting is complete, you can copy your data to the newly formatted disk.
How to Format a Disk to Use Between Mac and PC
If you want to format a disk to copy data between a Mac and a PC, select exFAT from the list of format options and follow the above steps to format the disk.
How to Format a Disk for Use with Time Machine
If you’re using Time Machine, which still uses HFS + (Mac OS Extended), choose APFS if you have the option to format the disk you’ll be using for Time Machine.
Frequently Asked Questions (FAQs)
1. Can I format a Mac’s internal drive using Disk Utility?
No, you cannot format the Mac’s internal drive using Disk Utility while it’s in use. You’ll need to start up in Recovery Mode and then use the Disk Utility tool to format the drive.
2. Will formatting a disk erase all data on it?
Yes, formatting a disk erases all data on it, so make sure to back up any data you want to keep before formatting.