How to Transfer Mac Files to an External Hard Drive

by Jeff Grundy
Mac computers require no special software drivers for external FireWire or USB hard drives.

Mac computers require no special software drivers for external FireWire or USB hard drives.

Modern Mac computers ship with relatively large capacity hard drives capable of storing thousands of documents, photos, music tracks and videos. Nevertheless, even the largest Mac hard drives fill up eventually and require the occasional spring cleaning. You can free up a considerable amount of space on your Mac computer's internal drive by moving files you don’t use often to an external FireWire or USB hard drive. Connecting and using an external drive with your Mac system is not only a good way of adding storage space to you system, but also helps to prevent loss of important files by serving as a portable backup device.

Connect the AC power adapter to the FireWire or USB hard drive if it has one, and then plug it into an electrical socket or power strip.

Connect the small end of the data cable to the hard drive, then connect the other end to an empty FireWire or USB port on your Mac. If the hard drive has a power switch, set it to the "ON" position. Wait a few seconds for your Mac to detect the external drive and mount it as a removable storage device automatically. A mounted volume icon for the external drive appears on the Mac desktop.

Double-click the mounted volume icon on the Mac desktop to open a new Finder window and display the contents of the external hard drive. Press the "Command-Shift-N" keys to create a new folder on the external drive, then rename it with a descriptive folder name.

Click "File" on the Finder menu bar, then click "New Finder Window." A second Finder window appears on the screen. Double-click the folder that contains files or folders you want to transfer to the external hard drive.

Highlight the folder and file names you want to transfer, then drag them to the new folder you created on the external hard drive -- the new folder should still appear in the first Finder window. Copy other files and folders to the external hard drive as needed by dragging and dropping them onto the new folder name.

Close both Finder windows after you finish transferring files.

Drag the volume icon for the external drive to the Trash icon on the desktop, then disconnect the external drive from the Mac computer.


  • A few modern Mac models use Thunderbolt ports rather than FireWire. If you want to use a FireWire drive with a Mac that has a Thunderbolt port, you can purchase an adapter from Apple.


  • If you use an external drive previously used with a Windows PC, you probably need to reformat it before you can use it with your Mac. Most Windows drives use the NTFS file system, while Mac external drives must use “exFat” or “Fat32.” To format the drive on your Mac, open a new Finder window, open the "Application" folder, then "Utilities." Double-click "Disk Utility" and highlight the device name of the external hard drive. Click the "Erase" tab and select "MS-DOS File System." Click the "Erase" button to format the drive. Note that if you format the drive, the process erases all data from the external storage device.

About the Author

Jeff Grundy has been writing computer-related articles and tutorials since 1995. Since that time, Grundy has written many guides to using various applications that are published on numerous how-to and tutorial sites. Born and raised in South Georgia, Grundy holds a Master of Science degree in mathematics from the Georgia Institute of Technology.

Photo Credits

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