How to Fix External Hard Drive Not Recognized on Mac [6 Proven Solutions]

External hard disk drives (HDDs) are one of the most important storage devices for personal computers. Their large storage capacity can hold vast amounts of data, especially big movies, photos, and videos. Plus, because they're portable, you can use them to transfer data between different computers. Or, if compatibility isn't an issue, you can use them across multiple devices and platforms!

But what to do if your Mac is not recognizing external hard drive? How would you proceed with tasks like data copy, data transfer, data backup, or anything that requires an external USB storage drive?

Why is an external hard drive not being recognized? The possible reasons could be...

There are many reasons why your hard drive might not be showing up when you connect it to your Mac. Something is definitely awry, but don't worry – some of these issues are easy to fix, while others may take a little more work.

Usually, an external hard drive not recognized issue is related to the connector you're using, a damaged file system, partition issues on the external HDD (like bad sectors), outdated drivers, or a virus infection on your Mac. All these can be potential reasons why your Mac is not detecting or recognizing the external hard drive.

Follow these 6 tips to fix a Mac that doesn't recognize an external hard drive. You'll find that most of the workable solutions revolve around Disk Utility (Tips #3-#5), a default app pre-installed on all Macs – meaning you won't have to pay to fix an external hard drive that your Mac won't read.

#1. Check the connection

The first concern is connectivity. This is easily identifiable and the most common reason why an external hard drive might not show up. There are a few ways to check for connectivity issues, primarily the USB port and the connecting cable.

• Make sure that the USB/eSATA cable is connected securely to the USB port, and isn't loose. • Are there other available USB ports? Try connecting the drive to a different USB port. See if the issue continues. • Do you have only one USB port available? If so, try connecting another device that can plug into a USB port, and see if your Mac recognizes it. • Otherwise, can you get access to another Mac? Try connecting the drive to a different Mac. Does it appear there?

If all of the above apply to you, it's likely a connectivity issue that you can resolve by trying a different cable or USB port. If none of these apply to you, continue on to the next solution.

#2. Adjust settings in the Apple Finder preferences

You can only see the external hard drive icon on your Mac's screen if you have the Show External Disks option enabled in Finder preferences.

Step 1: On your Mac, click the Finder icon in the Dock, then choose Finder > Preferences.

Step 2: In the General tab, you need to make sure that the items to be displayed on the desktop are checked, particularly the External Disks option. (If it's already checked, try the other methods.)

Close the Finder Preferences window. You should see your external drive on the Desktop.

#3. Disk Utility - Mounting an External Drive

Usually, your Mac should automatically mount any connected hard drive through one of its USB ports so that you can read from and write to it. Occasionally, an external hard drive won't mount on a Mac and therefore won't show up. However, you can manually mount an external hard drive on a Mac with Disk Utility, the hard drive management app that comes pre-installed on macOS.

If this is the case, you might see error messages when you open Disk Utility that suggest the problem causing your external hard drive not to show up is a mounting issue – that your Mac can't mount the disk.

How to Recover Data from an Unmounted External Hard Drive on Mac

When your Mac fails to access or recognize an external hard drive, you can check it in Disk Utility. If it shows as unmounted, you need to mount the external hard drive and make it recognizable.

Step 1: To open Disk Utility (which you'll need for both #Solution 4 and #Solution 5), click the Finder icon in the Dock > click "Applications" in the Sidebar > double-click the "Utilities" folder > and then double-click "Disk Utility" to launch it.

Step 2: In the left sidebar, select your external drive, then click “Mount.”

If that doesn't work, you may need to repair the disk.

#4. Use Disk Utility to Check and Repair External Hard Drive Damage

The First Aid feature in Disk Utility can check for and repair disk errors, such as a damaged file system or bad sectors.

Step 1: While in Disk Utility, select your external drive in the left sidebar, then click the “First Aid” button.

Step 2: Disk Utility will scan the disk for errors and repair them if necessary. Click Run to proceed.

#5. Use Disk Utility to Format External Hard Drive to APFS/ExFAT

Formatting the disk is a simple and effective way to fix most hard drive issues, which are usually logical errors. macOS might not recognize the drive if the external hard drive's file system is corrupted or incompatible with the current macOS.

Step 1: In Disk Utility, click the “Erase” button this time to format the external drive you've selected.

Step 2: The most critical step here is to choose the right file system for your external drive. From the “Format” drop-down, you should select either APFS or ExFAT, which macOS can recognize, and then click “Erase.”

#6. Recover Data from External Hard Drive Not Recognized by Mac

The above five tips have been tested to effectively fix external hard drive not working on Mac issue, and most of the methods are based on the default disk utility on Mac, so you may be able to fix the unrecognized external hard drive on Mac for free by yourself. When the external hard drive not showing up or not being recognized on Mac causing data loss, you can download a free Mac hard drive recovery tool to perform full data recovery.

Step 1: Search for the missing file

Connect the external hard drive to your Mac correctly. Launch Disk Drill for Mac, select the external hard drive, and then click “Search for lost files” to find deleted or lost files on the device.

Note: Before you recover data, it is recommended that you click “Disk Backup” from the left sidebar and create a backup of the external hard drive to prevent further data loss. After backing up the external hard drive, the software can recover data from the backup of the external hard drive. Then, you can remove the external hard drive and use it again.

Select the external hard drive and click “Search for Lost Files”.

'Step 2: Search and find the lost file'

After the scan, all file types will be shown on the left. Choose the file type and look for the needed files on the external device.

Step 3: Preview and recover

Click on the file to preview it, then select the files you want to recover and hit the “Restore” button. You can save your data to both local and cloud drives.