How to Compare Checksums of Two Files

To compare checksums of two files, compute a hash such as SHA-256 for each file and check whether the two hashes match. If they do, the files are byte-for-byte identical, regardless of name or size. If the hashes differ, even a single changed byte will surface it. On Windows you can run CertUtil -hashfile file SHA256 in a terminal, on Linux sha256sum file, and compare the two hex strings by eye or with a diff. For a faster path, paste both files into the free FolderManifest checksum calculator and it returns both hashes side by side so you can confirm a match in one click. This is the standard way to verify a download, a transfer, or a backup copy.