Check a copy with its checksum

AirSCP can make sure that a copied file is exactly the same as the original. It compares their SHA-256 checksums: a fingerprint of every byte in the file.

Steps

  • One transfer: right-click a finished transfer in the Transfers list and choose Verify with Checksum.
  • Every transfer: turn on AirSCP ▸ Settings ▸ Verify transfers with SHA-256. Each file is checked as soon as it arrives.

The status then says:

  • Verified: the copy and the original are the same.
  • Mismatch (red): they differ. The copy was damaged, or one of them changed after the copy was made. Click Retry to copy the file again. AirSCP replaces the bad copy and checks the new one.
  • Not verified: AirSCP couldn’t check it. Point at the status to see why.
The Transfers list with a verified upload

Tips

  • Only single files are checked, not folders or archives.
  • The server works out its checksum with sha256sum or shasum. Accounts that allow file transfers (sftp) only can’t run them, so their copies show Not verified.
  • Checking reads the whole file on both sides, so big files take longer.
  • To see the checksum, point at Verified in the list.