So, you just bought an external hard drive and wanted to use it on your Mac. But somehow, macOS doesn't allow you to write data to the drive. That's all because it's been initialized with Windows NT File System (NTFS), which is primarily for PCs. Apple Mac machines support a different file system. In this post, I'm going to show you how to format your external drive for a Mac compatible file system i.e. Mac OS Extended (Journaled). Just follow this easy step-by-step guide and you're all set.

Important note: If you have useful files stored on the external drive, be sure to copy or transfer them to another safe place prior to formatting. The operation will erase all data and your files will be gone for good.

You could use a recovery program like to retrieve them, but the odds of recovery vary. Pro tip: If your external drive has a large volume, like mine - a 2TB Seagate Expansion - I highly recommend you also create multiple partitions. I'll also show you how to do that below. Most External Hard Drives Are Initiated with NTFS During the last several years, I've used several removable drives, including a 500GB WD My Passport, 32GB Lexar flash drive, and a few others.

Three weeks ago, I bought a brand new to backup my MacBook Pro before I updated to the latest macOS, 10.13 High Sierra (also see I encountered). When I connected the Seagate to my Mac, the drive icon showed up like this. What is NTFS? I'm not going to explain here; you can read more on. The problem is that on macOS, you can't work with files saved on an NTFS drive unless you use a paid app. How to Format an External Drive to Work with Mac (from NTFS to Mac OS Extended)?

Note: The tutorial and screenshots below are based on macOS Sierra 10.12.5. They might be different if your Mac has a different version. Step 1: Open Disk Utility.

The quickest way to do this is a simple Spotlight search (click the search icon on the upper right corner), or go to Applications Utilities Disk Utility. After clicking 'Partition', you'll see this window. Located on the left is a big blue circle with the name of your external drive together with its volume size. What you need to do next is click the add '+' button to increase the number of partitions on your external disk. Then allocate the desired volume to each partition. You can do that by clicking the small white circle and dragging it around.

After that, you can rename each partition and define a file system for it. Step 3: Confirm your operation.

Photo by Sharon Vaknin/CNET If you need to expand your storage space with an external hard drive and you use both Mac and PC, you'll likely run into a few obstacles. Hard drives advertised as being compatible with Windows and Mac OS may have misled you into thinking you could actually use one hard drive for both computers. You can, but not out of the box. Most external hard drives (HD) are sold in a format called NTFS, which is designed to work with Windows. Macs read and write to a different format, called HFS+. Another format, called FAT32 is compatible with both OS platforms. Here's a look at how the different HD format types function: FAT32 (File Allocation Table) - Natively read/write FAT32 on Windows and Mac OS X.

Maximum file size: 4GB - Maximum volume size: 2TB NTFS (Windows NT File System) - Natively read/write NTFS on Windows. Read-only NTFS on Mac OS X - Native NTFS support can be enabled in Snow Leopard and above but has proven instable. Maximum file size: 16 TB - Maximum volume size: 256TB HFS+ (Hierarchical File System, aka Mac OS Extended) - Natively read/write HFS+ on Mac OS X - Required for Time Machine - Maximum file size: 8 - Maximum volume size: 8EiB Isn't FAT32 the obvious solution? According to the list above, formatting your hard drive to FAT32 so that you can read and write on either OS seems like the obvious solution.

The video and directions below will guide you through the process, but before you format your HD to FAT32, beware of these drawbacks. FAT32 offers no security, unlike NTFS, which allows you to set permissions. If your HD gets into the wrong hands, that person will be able to access your data. The max size for any given file stored on a FAT32-formatted HD is 4GB. So, for example, if you want to store a 9GB movie, it will be impossible. In general, FAT32 drives are more susceptible to disk errors.

It's not a huge issue, but FAT32 is less efficient at storing files. Its large cluster sizes waste disk space, unlike the other HD storage formats. 2:55 If you've considered these issues and would still like to use FAT32, this video will guide you through the process of formatting your HD to FAT32 using a Windows or Mac PC: OK, what are my alternatives to using FAT32? The good news is, it's not FAT32 or nothing.

The alternative solutions do require more tinkering, but if you do not want to risk FAT32's lack of security, choose from one of the following alternatives. Option 1: Format to NTFS, and use NTFS-3G to read/write on Mac. If you keep your hard drive's out-of-the-box NTFS format for all the reasons FAT32 displeases, there's a workaround that will allow your Mac to read and write files to the drive. Is an open-source program that, when coupled with, will let you use your NTFS drive on your Mac. However, it is an open-source program, so use it at your own risk. Many have vouched for its success, but others complain about bugs.

The commercial solution, which will give you access to support and software updates, is. It's $20, offers Lion support, and you get a five-day trial to try before you buy. Option 2: Format to HFS+, and use HFS Explorer to read/write on PC. Conversely, you can format the HD to HFS+ and use HFSExplorer for Windows to read and write to the Mac-formatted hard drive. To get started, you'll first have to format the hard drive from NTFS to HFS+. Here's how: Plug your HD into the Mac and open Disk Utility, which can be accessed by searching for it in Spotlight.

Then, select your hard drive from the left sidebar. Now go to the Erase tab. In the Volume Format list, select Mac OS Extended (Journaled). Then, click Erase at the bottom to format the drive.

Please note that this will complete erase the drive. Any data you want to keep on that drive must be backed up elsewhere first.

Now that the hard drive is formatted to HFS+, on your Windows machine to get read and write access to the drive. This is an open-source program, so use it at your own risk.

Formatting External Hd For Mac

Alternatively, you can opt for paid software like instead. Option 3: Create two partitions on your hard drive to use with each OS, separately. This solution is a little different than the previous two because instead of having one hard drive that works with both machines, you're splitting your HD into two sections, each dedicated to a different OS. For example, if you have a 1TB hard drive, 500GB of storage can be used with your Windows computer, and 500 will be dedicated to your Mac computer. You won't be able to write to the Mac side from your Windows computer, and vice versa, but it's a good solution for people who want all the advantages each format has to offer for its respective system.

Here's how to do it: Step 1: Connect the empty external HD to your Mac and launch Disk Utility. Select the drive from the left sidebar, then click the Partition tab. Under Partition layout, select '2 Partitions.' Now, drag the boxes to adjust the size of each partition.

Format External Hard Drive For Mac Seagate

For example, you might want more storage for your Mac than you do for your PC. Now, click on the top partition, name it 'Windows,' and change its format to MS-DOS. Then click the second partition, name it 'Mac,' and change its format to Mac OS Extended (Journaled). Give your settings a final lookover and click Apply. Step 2: Plug the hard drive into your Windows PC. Open the Start menu and search for Disk Management.

Format External Drive For Mac And Windows

Select the search result and the Disk Management utility will launch. In the left sidebar, you should see your hard drive and its partitions.

Right-click the Windows partition and select Format. In the Format dialog box, under File System, select FAT32. Click OK and complete the format process. With these three options you'll be able to take advantage of either platform's offerings, be it Time Machine support or security options. In the end, you may end up using FAT32 for its simplicity, but don't say I didn't warn you about the risks.