What to do if External Hard Drive is in Read Only on Mac

External HDD stuck in Read Only on Mac

Prerequisites: HDD Connected to Mac

Difficulty Level: Member • Nerd • Platypus

Estimated Time: 15 minutes 

Expected Outcome: Your HDD is out of read only mode

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Method 1: Change Drive Permissions on macOS

Try manually changing the permissions using Finder. To change permissions on an external hard drive on Mac:

Step 1. Right-click your external hard drive in Finder and click “Get Info.”
Right-click menu on external drive

Step 2. Scroll down to the bottom of this new window and click the toggle beside “Sharing & Permissions” to expand these settings.
Sharing permissions tab in the Get Info window

Step 3. Under the “Privilege” column, click the entry beside your username (or “everyone”) and select “Read & Write.”
User's read and write permissions in Get Info window

Method 2: Use Disk Utility’s First Aid Function

If changing the permissions manually doesn’t work, your drive may have disk errors. The native macOS tool Disk Utility, which has a tool called “First Aid” that automatically scans for and repairs errors. To use First Aid to fix an external drive or USB drive read only on Mac:

Step 1. Open Finder > Applications > Utilities > Disk Utility.
Disk Utility icon in the Finder Applications folder

Step 2. Click the “View” button on the top-left corner of the middle pane and select “Show All Devices.”
Show All Devices button in Disk Utility

Step 3. Select your external hard drive from the list and click the “First Aid” button at the top of the Disk Utility window.
First Aid button in Disk Utility

Step 4. In the dialogue box that appears, click “Run.”
Run First Aid button in Disk Utility

Method 3: Format Your Drive

macOS can natively read & write on FAT32 and exFAT disks, so you’ll need to format your drive to one of these file systems. You can easily do this using Disk Utility:

Formatting totally wipes all data from the disk. You will have to use a tool called “Data Recovery Software” to restore your data after formatting it.

Step 1. Launch Disk Utility (Finder > Applications > Utilities > Disk Utility).
Disk Utility icon in the Finder Applications folder

Step 2. Click the “View” button on the top-left corner of the middle pane and select “Show All Devices.”
Show All Devices button in Disk Utility

Step 3. Select your external hard drive from the list and click the “Erase” button at the top of the Disk Utility window.
Erase button in Disk Utility

Step 4. Name your external drive, choose “ExFAT” for the format, and “GUID Partition Map” for the Scheme. Then, click “Erase.”
Format settings in Disk Utility