Problem solved by Diff Anything
Compare two drives on your Mac, find missing and changed files, and check large files by their hashes before erasing the old drive.
See it in the app
No accounts, cloud comparison service, analytics, or telemetry.
The problem
You copied an old external drive to a new SSD. Before erasing the old drive, you need to know whether every file arrived and whether the copies still contain the same data. Matching names, sizes and dates alone cannot answer that.
The solution
In Diff Anything, choose Compare two folders and select the old drive on the left and the new drive on the right. The comparison includes subfolders and lists missing, added and changed files. Turn on Compare hashes in Folder options to verify the content of large files too. Everything runs locally on your Mac; no AI is involved.
01 / Drive comparison
Left only means the file exists on the old drive but is missing from the new one. Right only means it exists only on the new drive. Changed means the file differs. Matching files are hidden by default.
02 / Drive comparison
By default, files up to 5 MiB are checked by content. A larger file with the same size on both drives is marked Unverified. Enable Compare hashes in Folder options to read and compare its content too. Hashing a large drive takes time because the files must be read.
03 / Drive comparison
Hidden files, including hidden system files, are excluded by default. Turn on Hidden files in Folder options if they belong in your check. Each side can contain up to 500,000 files and folders; for larger drives, compare the main folders one at a time.
04 / Drive comparison
The free version shows the first 100 folder results and allows 10 new comparisons per day. Pro shows complete folder results and adds folder copy and synchronization. You can also copy files with your usual file manager and reload the comparison. A drive comparison checks files and folders; it does not clone a disk or verify its bootability.
Clear answers
Yes. Connect and mount both drives so they appear in the file picker, then select each as a folder. Your files are read locally and are never uploaded.
No. Two files can have matching names, sizes and dates but different content. Use Compare hashes to check the content of large files rather than treating Unverified as a match.
Three short steps
Choose Compare two folders, then select the old drive under Locations in the file picker.
Select the new drive on the right and read the files listed as Left only, Right only or Changed.
Turn on Compare hashes in Folder options to check large files, then copy missing or damaged files again and reload the new side.
Available for macOS and Windows