How do I transfer my macOS to a new hard drive?


When you get a new hard drive for your Mac, you’ll likely want to transfer your existing macOS installation and data over from your old drive. This allows you to migrate your operating system, user accounts, applications, files, and settings to the new drive without having to start completely from scratch. There are a few reasons why you may want to transfer your macOS to a new hard drive:

  • You want to upgrade to a larger or faster hard drive to improve performance
  • Your old hard drive is starting to fail or is having issues
  • You want to move your macOS installation to an SSD for faster speeds
  • You need to replace your hard drive due to damage or failure

The main process involves first backing up your data, checking hardware compatibility, erasing and formatting the new drive, and then using Apple’s Migration Assistant tool or manually copying files to transfer everything over. With some adjustments afterwards, you can fully migrate your macOS system and keep all your apps, files, and settings intact.

Back Up Your Data

Before transferring your macOS to a new hard drive, it is critical to back up your important user data. Loss of data is the biggest risk when migrating your operating system, so protecting your files, photos, music, documents, and settings should be the first step. The best practice is to use Apple’s built-in Time Machine tool to back up everything to an external hard drive or wireless network storage device.

Time Machine will automatically back up your entire Mac on an hourly basis whenever the backup drive is connected. This provides versioning so you can restore previous versions of a file if needed. Time Machine will also back up system files in case you need to restore your entire system.

To set up Time Machine (Apple support):

  • Connect an external HDD or wireless network drive with at least 2x the storage capacity of your Mac’s drive.
  • Open System Preferences and click on Time Machine.
  • Click Select Backup Disk and choose your external drive.
  • Turn Time Machine on.

Time Machine will immediately start a full backup of your drive which may take hours. Let the initial backup complete before proceeding with your macOS migration. You now have peace of mind knowing your data is protected.

Check Hardware Compatibility

Before transferring your system to a new drive, it’s crucial to verify that your Mac model is compatible with the new drive. The physical size, connector type, and communication protocol of the new drive must match up with your Mac’s internal drive bay to ensure proper installation and operation.

Most newer Macs use PCIe or SATA solid state drives (SSDs), while some older models use SATA hard disk drives (HDDs). You’ll need to match your Mac’s drive connector – 2.5″ SATA SSDs for 13-inch models, M.2 NVMe SSDs for recent MacBooks Air and Pro. For iMacs, you can likely upgrade to a larger SATA HDD/SSD.

Additionally, check that the drive’s rated speed and bandwidth meets your performance needs. Faster PCIe 4 SSDs offer sequential read/write speeds up to 7GB/s but may not provide full benefit in older Thunderbolt 3/USB 3 Macs.

Consult EveryMac’s Mac SSD Upgrade Compatibility Guide to identify compatible replacement drives for your specific Mac model. Also check manufacturer forums or contact Apple support if unsure.

Verifying hardware compatibility in advance will ensure a smooth drive swap and prevent issues with getting your Mac to recognize the new drive down the road.

Erase and Format the New Drive

Before the new drive can be used as a startup disk, it must be erased and formatted properly for macOS. Here are the steps to erase and format the drive:

  1. Connect the new drive to your Mac using a USB, Thunderbolt, or other connection.

  2. Open Disk Utility on your Mac. You can find it by searching Spotlight or in Applications > Utilities.

  3. In Disk Utility, select the new drive from the sidebar.

  4. Click Erase at the top. Choose a name for the drive, format as APFS, and click Erase.

  5. Once completed, click Done. The new drive will now show up empty and formatted for macOS.1

With the new drive erased and formatted, it is now ready to have macOS and your data transferred over.

Use Migration Assistant

The easiest way to transfer your macOS system and data to a new hard drive is by using the Migration Assistant tool that comes built-in to macOS. Here are step-by-step instructions for using Migration Assistant:

First, make sure both your current Mac and the new hard drive are connected. The new drive should be formatted and mounted but does not need to have macOS installed yet.

On your current Mac, open the Migration Assistant app located in Applications > Utilities. Migration Assistant will search for the new hard drive and recognize it as a destination to transfer to.

When you see the new hard drive listed, select it and click Continue. Migration Assistant will ask what information you want to transfer. Choose the option to transfer “everything” to move your entire user account, applications, settings, and files.

Migration Assistant will begin the process of copying everything over. This can take some time depending on the amount of data being transferred. Let the process complete – do not disconnect either computer during transfer.

Once finished, your new hard drive will be a clone of your old one and ready to boot up. You can then install it in your Mac and boot from it directly.[1]

[1] “Transfer to a new Mac with Migration Assistant.” Apple Support,

Transfer Manually

As an alternative to Migration Assistant, you can manually transfer your files and macOS to the new hard drive. Here are the steps:

  1. Connect both your current startup drive and new drive to your Mac.
  2. Open Finder and navigate to your user account folder (e.g. Macintosh HD/Users/YourName).
  3. Drag and drop all user folders like Documents, Pictures, Music etc. to the new drive.
  4. Use the Finder’s Go menu and select “Go to Folder.” Enter “/Applications” and copy over all apps to the new drive.
  5. Copy over any other files/folders you need from your old drive.
  6. Go to your old drive and copy the macOS installer to the new drive. You can find this in /Applications.
  7. Reboot your Mac and hold the Option key to select the new drive and macOS installer.
  8. Run the macOS installer on the new drive to install the OS.
  9. Once installation is complete, you can set the new drive as your startup disk.

This process allows you to manually migrate your files, settings and apps instead of using Migration Assistant. It takes more time and effort, but gives you full control over what gets transferred.

Reinstall Applications

After transferring your data to the new hard drive, you’ll likely need to reinstall any third party applications that didn’t transfer over. Here are some tips for reinstalling your apps smoothly:

Check the Applications folder on the new drive to see which apps transferred over. For any missing apps, you’ll need to re-download the installers from the developer websites.

If you have apps purchased through the App Store, you can open the App Store on your new drive and go to the Purchases tab to download those apps again. Your purchase history should carry over.

For Adobe apps like Photoshop or Premiere, you can download the creative cloud app to reinstall them. Log in with your Adobe ID to access your purchased apps.

Apps like Microsoft Office will need to be reinstalled from their respective websites. You may need your license keys handy for reactivation.

If you have any apps that require serial numbers or activation codes, gather those before reinstalling. Some apps may allow you to deactivate on the old machine first.

Check the app websites for guidance on transferring licenses or reactivating apps on a new machine. This process varies depending on the developer.

Test your reinstalled apps to make sure they are working properly on the new hard drive. Reinstall any addons or plugins that are missing.

Update Drivers

After transferring your data and applications to the new hard drive, you may need to update some drivers for the new hardware configuration. Here are the steps for updating drivers on your Mac:

1. Click on the Apple menu and go to App Store. Look for any available updates to macOS and install them. macOS updates often include driver updates.

2. For more specific driver updates, go to System Preferences > Software Update. Check if there are any available updates.

3. If you have any peripherals connected via USB, Thunderbolt or other ports, check the manufacturer’s website for driver updates. Download and install any updates available.

4. For graphics drivers, go to System Preferences > Software Update. If any graphics driver updates are available, install them.1

5. If you experience any issues with external displays, wifi, Bluetooth or other components after the transfer, reinstalling or updating drivers can often resolve them.

Following these steps will ensure your Mac’s drivers are up to date for the new hardware configuration after transferring to a new hard drive.

Adjust Settings

After transferring your data and applications to the new hard drive, you may need to adjust some system settings and preferences in macOS. Some key settings to review include:

Display resolution and color – Check if the display resolution and color settings carried over properly to the new drive. Go to System Preferences > Displays to adjust the resolution and color profile if needed.

Startup disk – Make sure the new hard drive is set as the startup disk. Go to System Preferences > Startup Disk to select the new drive. You can also hold down the Option key on boot to select the boot drive.1

Energy saver settings – The energy saver settings may need to be re-configured for the new hardware. Go to System Preferences > Energy Saver to customize settings like display sleep and hard drive sleep timers.

Touch ID and Apple Pay – If your Mac supports Touch ID, you may need to re-enable it in System Preferences > Touch ID. Check that Apple Pay is still enabled as well.

Keyboard settings – Check that keyboard settings like keyboard repeat rate and delay carried over properly in System Preferences > Keyboard.

Trackpad settings – Review the trackpad settings under System Preferences > Trackpad to make sure gesture preferences transferred correctly.

Printers and scanners – You may need to re-add printer and scanner drivers on the new hard drive under System Preferences > Printers & Scanners.

Updating these settings helps personalize your Mac and ensure proper functionality after transferring to the new drive.

Perform Post-Transfer Tasks

After you have transferred your data and applications to the new hard drive, there are some post-transfer cleanup tasks and checks you should perform to ensure proper functioning:

  • Empty the Trash on your old hard drive to free up space
  • Check that all your apps transferred properly and reinstall any that didn’t
  • Make sure Handoff is enabled so any tasks started on your old Mac will transfer to the new one (Apple Support)
  • Check iCloud and make sure all data synced properly
  • Update mail clients and accounts to use new hard drive
  • Update login items and System Preferences
  • Customize dock, desktop picture, and settings on new hard drive

Following these tips will help ensure a smooth transition to your new hard drive. Allow some time after the transfer to cleanup and adjust settings before considering the transfer fully complete.