The most obvious reason that causes you can't transfer files from MacBook to an external hard drive is the incompatible file system. So the first thing you need to do is to check the file system of your external hard drive. Here's how:
- Connect your external hard drive to your MacBook.
- Go to Finder > Applications > Utilities > Disk Utility and double-click to open it.
- Select your drive and the file system will show in the right panel.
If your file system is NTFS formatted, you can't write, copy, transfer, delete, or rename files on it but read it on your MacBook. You can choose to format your external hard drive with a Mac-compatible file system or mount it with third-party software. If you don't want to lose data, third-party software is the best choice.
iBoysoft NTFS for Mac is an NTFS reader that can help you to mount your external hard drive in read-write mode on your MacBook without formatting, so that you can take full use of your NTFS drive on your MacBook.
Step 1: Download, install, and launch iBoysoft NTFS for Mac.
Step 2: Connect your drive to your MacBook and wait for it to mount successfully.
Step 3: Enable System Extensions by iBoysoft to grant full disk access if it is required.
Now, you can freely transfer your files from your MacBook to an external hard drive.
If your external hard drive is not NTFS formatted, here are some other reasons and fixes for you to understand why you can't transfer your files from MacBook to an external hard drive.
- System files. Some system files on your Mac are protected and cannot be copied or transferred to an external hard drive.
- Files are in use. The files you want to transfer are currently in use by another application or process on your MacBook. You can relaunch Finder or restart your MacBook to fix it.
- Files are too large for the files system of your external hard drive. For example, if your files are larger than 4GB on a FAT32 formatted drive, you will not be able to transfer them without splitting them into small parts.