Seagate Expansion 1TB for Mac, Want it but can I use on Mac?

By Paul Gregory / January 11, 2019
Seagate Expansion 1TB For Mac

Seagate Expansion 1TB for Mac?

The answer is Yes you can have it on your Mac.

Whether you are thinking about buying this Seagate portable for your Mac Or you already have one?

In this post I give you an overview of this extremely popular drive and tell you how you can take advantage of its good price, connect up and use this portable on your Mac.

For those in a hurry to find out how to connect, format and use on a Mac take a look at the table of contents and jump to the section you need.

The Seagate Expansion is right up there in the midst of the best selling portable external hard drives and for good reasons. It is easy to use, the price per terabyte is competitive and its small size makes it convenient to use, store and take with you.

Seagate Expansion 1TB Box

Seagate Expansion 1TB Portable External Hard Drive

Use the above link to look up the current price on Amazon

Overview of the Seagate Expansion Portable

The Seagate Expansion drive is manufactured by Seagate Technology.

A company that has been around in the hard disk drive market place for many tens of years and their hard drives have a solid reputation for reliability and affordability. Seagate provide hard drives for high-end enterprise grade computing as well as this basic portable drive for the home or small business user.

What do I mean by a basic drive?

There is no special backup software sold with the Seagate Expansion portable, no hardware based password protection or encryption offered on the hard drive itself.

But not to worry, if you need this, the beauty of Mac OS is that the standard operating system can provide these facilities. I reveal how later.

Indeed personally, I have had a Seagate external hard drive that I bought as a backup device for my Mac back in 2010 and it’s still going strong.

Seagate Expansion Drive Capacity, Size and Weight

Portable Capacity 1TB and 2TB
Size 4.7” x 3.2” x 0.6”
Weight 6.4 ounces
Portable Capacity 4TB
Size 5.8” x 4.1” x 1.6”
Weight 8.32 ounces

The Seagate Expansion comes in 1TB, 2TB and 4TB capacities, which is plenty for most students and many professionals who use a Mac. You’ll see from the dimensions above the hard drive is both convenient in size and portable.

Remember although the Seagate Expansion is sold as a portable and is of a convenient size and weight to carry around, this drive is a mechanical drive. Which means that drive is less rugged than an SSD (Solid State Drive) and has moving components. A drop or a fall could damage the unit I would highly recommend carrying it around in a protective case.

Here are some of my preferred protective cases;

1. Lacdo Shockproof Carrying Case

2. Ginsco Hard Carrying Case for Portable External Drive

3. Amazon Basics External Hard Drive Case

Features of the Seagate External Hard Drive

Out of the box the Seagate Expansion is formatted to NTFS.

Which means that it will plug straight into a Windows PC. You can use the Seagate Expansion 1TB for Mac – it will just need reformatting first. Something that only takes a few minutes to do and is easy once you know how.

I cover how later.

Seagate Expansion Connecting Up to your Mac

The Seagate Expansion drive connects via USB and the drive and its cable is of the USB 3.0 standard and speed.

With a type A connection for the Mac end and a Micro USB type B at the Seagate Expansion drive.

Seagate Expansion USB 3.0 Cable

Seagate Expansion USB 3.0 Cable

This means that the cable will plug straight into those Mac’s with type A USB ports, which are the previous generation Macs (earlier than late 2016 models).

For those of you with the newest Macbooks who have Thunderbolt, or USB 3.1 ports, the Seagate Expansion’s supplied USB cable will not directly connect to those Macs. As the USB 3.0 and USB 3.1 connections are physically different.

You will need an USB cable with USB C/Thunderbolt connection at one end and a Micro USB type B at the other end or an adaptor cable.

My preferred USB cables to use for Macs with Thunderbolt ports are;

1. Apple USB-C to USB Adaptor

2. AmazonBasics USB Type-C to Micro-B

You can use the links above to view them on Amazon.

Do You Need a Thunderbolt Drive?

Unless you need the speed of Thunderbolt, (theoretical 10 GBits/sec minus USB overheads) the Seagate Expansion portable will be a lot cheaper to buy than Thunderbolt native external hard drives.

The performance level of the Seagate Expansion USB 3.0 external drive is fine for many home and office users who are looking to use the drive to store files and perform backups on their Macs.

In USB 3.0 testing, I observed 120 MBps writing speed and nearly 130 MBps reading speed, which are among the fastest in portable hard drives in its storage capacity category.

Can You use the Seagate Expansion for a Mac with Thunderbolt Ports?


The USB standard provides backward compatibility.

This means that if you plug this drive into a Mac with a Thunderbolt port (using a suitable USB cable) the drive will work just fine. Your Mac will pass files to the Seagate Expansion at the speed the hard drive is cable of.

Similar for those of us who have Macs with USB 2.0 ports. Those Macs have USB type A ports that means the USB cable supplied with the Seagate Expansion will plug straight in.

This time the Mac will send files to the drive at the speed the Mac is able to support so the file transfer rate will be at USB 2.0 speeds.

A fuller explanation of the USB ports and images are in my document called How to connect an External Hard Drive to a Mac


The Seagate Expansion 1TB, 2TB, 4TB are supplied with 2 years warranty which is industry standard for this type of consumer portable drive.

What’s in the Seagate Expansion Box When you Buy?

When shipped to you you’ll find your Seagate Expansion Portable hard drive, an 18-inch USB 3.0 cable, which is also compatible with USB 2.0.

Depending on how you use your Mac and where you need to put the Seagate Expansion portable you may find the USB 3.0 cable supplied is too short to be practical.

Don’t worry this is a standard type A to Micro B USB 3.0 cable so you’ll be able to get a longer replacement cable on Amazon.

In the box is also the Quick Start Guide.

You can see the Quick Start Guide here.

Why not take a look at his unboxing video and see for yourself.

Images and Video Credit: TJS Mind

How do you use the Seagate Expansion on a Mac?

For a Mac the Seagate Expansion is easy to set up and use.

Power up your Mac and plug the USB cable in.

Just make sure you have the right cable for your Mac – see the section above about physical connections for Mac.

The Seagate Expansion is a bus powered portable drive.

What does that mean?

This means that you will only need the USB cable as the USB cable is used for both power and transferring files.

No need to worry about carrying around a power cable and or plug adaptor.

Seagate Expansion Easy Connection to Mac

Seagate Expansion Easy Connection to Mac

Imagine finding yourself in another country and with an external drive that needs a separate power plug. Not only will you need another plug socket in addition to the one you need for your Mac but you may need a local power adaptor too.

No worries about that on this Seagate Expansion.

Now you have the drive physically connected what now?

To Format Seagate Expansion Drive For Mac

By default the Seagate Expansion comes pre formatted to NTFS to plug straight into a Windows PC. It will need reformatting for Mac.

Macs read and understand Mac OS Extended (Journaled) file system. When the Seagate Expansion is formatted for Mac OS Extended (Journaled) file system you can freely use the drive to store files on or as a drive for Time Machine to back up to.

Formatting is a process that only takes minutes.

Why would you bother with this?

While a Mac specific hard drive of course comes out of the box ready to plug in, you often play a extra for that …

I think for a mere few minutes of extra effort you can format your Seagate Expansion drive for Mac and use a drive that works great at a more affordable price when compared to Mac branded products.

To Format Seagate Expansion For Mac

  1. Log into your Mac and plug in the USB cable to connect up to the Seagate Expansion drive. You will see an icon appearing on your desktop representing the hard drive.
External Drive Icon On Desktop

External Drive Icon On Desktop

  1. You will be using a program called Disk Utility to format the drive. You start up disk utility by heading to your Mac’s dock at the bottom of the desktop and clicking on the Applications folder. Within that folder you will find the utilities folder click on that. Double click on the Disk Utility program.
Disk Utility In Application Folder

Disk Utility In Application Folder

  1. Once Disk Utility has started up you will see all the drives connected to your Mac. The Seagate Expansion will be listed under the ‘External drives’.
Seagate Internal External Drive List

Seagate Internal External Drive List Circled in Yellow

Click on the Seagate Expansion at the top level.

Select Seagate Expansion at the Right Level

Select Seagate Expansion at the Right Level

This is important as without selecting at the right level you can get random errors with formatting the Seagate Expansion drive.

  1. Then move to the top of the Disk Utility popup window and select Erase.

Erase is the part of the Disk Utility program that formats the disk for you but note that this process will remove all and any existing files on the disk. If you have used the Seagate Expansion on a Windows PC and it has files on it you want to save them, copy them off first.

Select Erase

Select Erase

  1. The next popup window is where you select the details to format the Seagate Expansion drive for Mac.

Give the Seagate Expansion a name, select

  • Mac OS Extended (Journaled),
  • GUID Partition Map

and then click on Erase. Mac OS will do its work and within a few moments the hard drive will be formatted ready for you to use on your Mac.

Should you see an error come up as you try to format, don’t worry, this seems to be something of a quirk with Mac OS Sierra. Just retry and it should be fine.

I have a document that goes into far more detail on formatting an external hard drive for a Mac. Please feel free to read it for backup information.

How to Format and Partition the Seagate Expansion for Mac YouTube Video

You can watch this 13 minute YouTube video by Acguevara. The video explains the formatting process really well. Watch and use alongside my notes and even the technically challenged can see how easy this is to do.

Seagate External hard drive how to set up on a Mac.

Image and Video Credit: Acguevara

How to Format Seagate Hard Drive for Mac and PC

For those users and households that have both Macs and Windows PCs and are looking to use the Seagate Expansion drive between Mac and Windows PC, note that the drive needs to be formatted to ExFAT.

Follow my format instructions above except in step 5 choose the ExFAT file system.

To format for Mac and PC:

Give the Seagate Expansion a name, use the up and down arrows to the right of the format option to reveal the other disk formatting options and choose ExFAT.

File System Formats

File System Formats

Do not choose MS-DOS (FAT) as that file system, it is old, has file size restrictions and you would only use it If you had to. Say for those devices that must use MS-DOS (FAT) operating system. And yes there are still a few about out there.

Choose ExFAT leave everything else the same as my instructions above, and then click on Erase.

Within a few minutes the whole drive will be formatted so that both your Mac and a Windows PC can read and write to the Seagate Expansion.

Want to have a Part of the Drive for your Mac and a Part for a Windows PC?

To do that you will need to partition up the drive into different sections.

I have an article on the site that shows you how. It just takes a few minutes more.

Take a look at my article External Hard Drive for Mac and Window PC.

It covers the steps for partitioning a hard drive and formatting each partition for what you need. The options are;

  • for Mac backup with Time Machine
  • Storing files
  • a shared partition for Mac and PC.

Now you have your Seagate Expansion all formatted ready to use. What now?

Using the Seagate Expansion 1TB on a Mac

Is as easy and as familiar as using the internal drives on your Mac.

The drag-and-drop features you’re used to using on your Mac or your PC are the same.

Now the Seagate is formatted you will see an icon representing your Seagate drive on the desktop.

New Drive Icon On Desktop

New Drive Icon On Desktop

Double click on it and a finder window will open up.

New Drive Empty Finder Window

New Drive Empty Finder Window

You can now create new folders, on your newly formatted Seagate drive.

Finder Create New Folder

Finder Create New Folder

Use all the usual file selection methods you are used to using to copy and paste or drag and drop files and folders from your Mac computer to the Seagate Expansion drive.

Be aware that if these file are the only copy of your files and something happens to your Seagate Expansion then you could lose them.

Ensure you have a copy of them elsewhere or better yet purchase two Seagate Expansions and have the second as a back up of your first.

When you are finished using the Seagate drive – if you have deleted files from it be sure to empty your trash, otherwise ghost images of the files could still appear.

And be sure to Eject the drive properly from your Mac by right clicking on the disk icon on your desktop and selecting Eject.

Right Click to Eject External Drive

Right Click to Eject External Drive

How to Use the Seagate Expansion to Backup Your Mac?

Time Machine is the software on a Mac that is used to backup your Mac to an external hard drive.

Format the Seagate Expansion to Mac OS Extended (Journaled) file system. Take a look at the steps above.

Ensure you have enough capacity on the drive.

Say you have 400 GB of data on an internal drive to backup then you will need at least a 400GB of capacity on the Seagate Expansion. Preferably twice the capacity as Time Machine can do odd things when the backup drive is too small.

So in this case will need 800 GB available on your Seagate Expansion external drive or at least an 800 GB partition to use for your Time Machine backup.

Connecting up the Seagate Expansion to Time Machine is a simple process.

To do;

  1. Plug in your Seagate Expansion and start up Time Machine. To find Time Machine go to spotlight search
Spotlight Search Symbol

Spotlight Search Symbol

Type in System Preference and double click when it comes up.

Time Machine in System Preferences

Time Machine in System Preferences

Select Time Machine from the System Preferences window

  1. Once in Time Machine should you have a slider to turn Time Machine on or off turn it to on,

You can check the tick box for Time Machine to back up automatically and another useful checkbox to use is the one at the bottom of the pop up screen to show Time Machine in the menu bar at the top of your desktop screen. Check that box too.

Select Add or remove backup disk

First Time Machine Window

First Time Machine Window

Take a look at the available disks, your Seagate Expansion disk or if you have created a backup partition on it the partition will be listed here.

Time Machine Available Drives

Time Machine Available Drives

Select your Seagate Expansion and click on ‘Use Disk’

And that’s it, your Seagate is now set up with Time Machine.

  1. To kick off a backup straight away, and as you have the Time Machine program on your desktop menu, head to the top of your desktop screen and click on the Time Machine symbol.
Time Machine At Top of Desktop

Time Machine At Top of Desktop

Click on it and select Backup Now from the Menu.

Time Machine Backup Now

Time Machine Backup Now

You can also click on the symbol while the backup is taking place to see the progress and to check when your backup is finished.

If this is the first backup of your Mac to the Seagate Expansion it could take some time while your Mac prepares the backup and if you have a lot to backup it could take a while to do the backup too. So be patient.

Plug your Mac into external power and leave the backup to happen in the background.

You can read more in my article on ‘How to backup a Macbook Pro to an external hard drive‘.

Be sure to eject the drive from the Mac when the backup has finished and when you wish to put your Seagate Expansion away.

This will to prevent file corruption issues.

Password Protect Seagate Expansion Portable Drive

What about Passwords and Data Encryption for your Seagate Expansion files?

The software freely available to you on your Mac will do that for you.

Using Disk Utility you can format the drive and add a password, Click on the security options on the Erase screen and choose the security option you want there. Or

using Time Machine you can select the check box to encrypt your backup on the screen where you pick your Seagate Expansion as the backup drive.

Take a look at the pictures above and you’ll see what I mean.

Beware these software features on a Mac are designed to be secure. Losing or forgetting your password will see you saying goodbye to your files. So keep the password access information secure.

The Verdict on Using the Seagate Expansion 1TB for Mac


  • The Seagate Expansion comes in at an affordable price
  • Plenty of storage space offered with 1TB, 2TB and 4TB options
  • Format compatible with both Mac and Windows PC. Interchange ability; use on one or other or create a partition to accommodate both Mac and Windows PC
  • Quick installation and easy use
  • Works with Time Machine
  • Many happy users


  • Basic no-frills design and features
  • No USB 3.1/Thunderbolt connectivity
  • Some users have reported reliability issues on this drive. It pays to have a backup in more than one place. Have multiple drives you backup to.

Last Words

The question we started this article with is – Seagate Expansion 1TB for Mac, I want it but can I use on Mac? The answer is if you want it then yes, you can definitely use it on a Mac. The Seagate Expansion 1TB Portable External Hard Drive is a great product for Mac. Most of its users swear by its reliable performance, great choice storage space, and ease of use from installation to file transfer. You should check it out and can by clicking on the link in this paragraph.

Want to see where the Seagate Expansion 1TB 1TB appears on my list of the Best External Disks for Mac.