At that place are all kinds of reasons why you might want to format a drive. Perhaps you are selling yous Mac and you want to completely erase it so that nobody can access your date. Or possibly yous are setting up an external drive for backups. Perhaps you lot want to copy something onto a bulldoze to share with a PC or some other Mac. Or information technology might be that you bought a drive to use with your Mac only to discovered it is pre-formatted for Windows.

Fortunately Disk Utility, congenital right into MacOS, can aid. And information technology'south easy to apply too.

Read our roundup of the best storage devices available now: Best storage options for Mac. Also take a expect at How to install and run Windows on a Mac.

Before we begin there are a few things you need to know, including the most important determination of all, which format to employ.

Nosotros also have a tutorial on using Disk Utility on a Mac hither. Other reasons you might want to employ Disk Utility include making a bootable macOS install bulldoze (covered here) and if you are doing a make clean install of macOS.

Which file format should I utilise?

At that place are a few file formats that you can use but the one that'south right for your circumstances depends very much on what you are going to be using the drive for. We'll describe them beneath, and yous'll be able to choose the i that suits you.

APFS (Apple File System) - This is the new file system that Apple bought to Macs with High Sierra and it will be the default if you are using that version of macOS. There are a number of things that are practiced near it - such as it being more efficient and more reliable. Y'all can cull an encrypted version and a case-sensitive version. Just it won't be readable or usable by a Mac that isn't running High Sierra, and Windows or Linux machines won't be able to read or write either. And information technology currently just works on SSDs or Flash storage. Read some of the good stuff about APFS here. For now we'd advise against formatting in APFS because it won't exist readable by Macs that aren't running High Sierra, but this may non thing to you.

MacOS Extended (Journaled) (likewise known every bit HFS+) - APFS replaced MacOS Extended as the default file system on the Mac when Apple launched High Sierra in 2017. If your Mac isn't updated to High Sierra it will offering MacOS Extended as the default. In that location's likewise the option of MacOS Extended (Journaled, Encrypted) which is a skillful choice if you are likely to be carrying your laptop or external drive around and don't want anyone to access the contents of the drive should you accidentally lose it. You lot tin can encrypt your bulldoze and require a password to access it. There's also an option of MacOS Extended (Instance-sensitive, Journaled, Encrypted) if you are probable to have file names that require capital letter letters. Windows can read HFS+ drives simply tin't write to them.

MS-DOS FAT (aka FAT32) - In FAT32'southward favour, it can be read and written by Mac, Linux Windows - and then you might want to use this if you regularly share drives with PC-owning friends or colleagues and want them to be able to admission the files y'all place on the drive. However, it's an older file system and files are limited to  4GB or smaller - so it'southward not much use if you are copying movie files for example. FAT32 offers no security and it'due south more susceptible to deejay errors.

ExFAT - this is similar to FAT32 to a higher place. Both Windows and Mac tin can read drives formatted with this. The primary deviation is information technology tin can shop files over 4GB.

NTFS - This is Windows' default file system. MacOS can only read NTFS, it can't write to it. Although there are tertiary political party tools that could let y'all to do so.

How to format an external drive for Mac

Here's how to format a drive if you are planning to utilise it with a Mac.

  1. Launch Disk Utility. Either head to Applications > Utilities, or tap Command + Space and start typing Deejay Utility.
  2. Once Deejay Utility is open up you'll run into the list of available drives on the left. Cull the drive you'd like to format. NOTE that formatting your drive will erase the contents, so make sure y'all back it up outset!
  3. Click on the Erase option from the 4 options available in the principal window.
  4. Disk Utility will automatically choose the format for you. This may exist APFS, or information technology may exist Mac Bone Extended (Journaled) depending on how the drive is currently formatted and whether you using macOS High Sierra or an older version of the OS. If you'd similar to use something else click on the Formatting options to reveal the drop-downwardly window. Choose your format you require depending on how you intend to utilize the formatted drive (see to a higher place for more than data about the format types).
  5. The next step is to give the drive a proper name.  This tin can exist anything you like, merely choose something obvious that volition requite you a hint as to what'south on in that location.
  6. Next, click the Security Options button. This will bring upward another window that enables yous to cull how you'd like the drive to be formatted, with a slider ranging from Fastest to Most Secure. This is an important step if you want to make sure that whatsoever files currently on the bulldoze are safely erased.
  7. Fastest will erase the drive past removing the header information, but will go out the underlying files intact, although they will be hidden. This means you or someone else could resurrect the files easily using data-recovery software, which isn't necessarily a skilful idea. Move the slider to the second option where it says "This selection writes a single pass of zeros over the unabridged disk." This volition overwrite the unabridged bulldoze one time.
  8. For college security, continue moving to the slider to the correct. The next footstep will requite you the pick to overwrite the drive iii times. Moving it the entire way to Most Secure will overwrite the drive vii times - merely y'all'll have to look quite a while (depending on the size of the bulldoze) before information technology will be available for you to employ again.Format a storage drive for Mac - Security
  9. Click on Erase and wait while the contents is erased and the drive is made ready. A progress bar volition show how the formatting of your drive is going and how long, roughly, information technology volition accept to complete.Format a storage drive for Mac - Formatted
  10. Now copy your files onto the newly formatted drive.

How to format an drive to employ with a Mac & PC

If yous want to format a drive and then that you can copy files between a Mac and a PC you lot'll want to follow the tutorial above, but choose ExFAT from the listing of format options.

How to format a bulldoze for utilize with Fourth dimension Motorcar

We have a tutorial on creating a Time Machine drive here, but perhaps the big question in the context of this item tutorial is which format to use.

Time Machine yet uses HFS+ (that's Mac Os Extended). If you have the option to format the drive you volition be using for Time Machine using APFS don't. Time Machine tin can't currently use APFS.