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
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.”
Step 2. Scroll down to the bottom of this new window and click the toggle beside “Sharing & Permissions” to expand these settings.
Step 3. Under the “Privilege” column, click the entry beside your username (or “everyone”) and select “Read & Write.”
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.
Step 2. Click the “View” button on the top-left corner of the middle pane and select “Show All Devices.”
Step 3. Select your external hard drive from the list and click the “First Aid” button at the top of the Disk Utility window.
Step 4. In the dialogue box that appears, click “Run.”
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:
Step 1. Launch Disk Utility (Finder > Applications > Utilities > Disk Utility).
Step 2. Click the “View” button on the top-left corner of the middle pane and select “Show All Devices.”
Step 3. Select your external hard drive from the list and click the “Erase” button at the top of the Disk Utility window.
Step 4. Name your external drive, choose “ExFAT” for the format, and “GUID Partition Map” for the Scheme. Then, click “Erase.”