# b2sum > Calculate BLAKE2 cryptographic checksums. > More information: . - Calculate the BLAKE2 checksum for a file: `b2sum {{filename1}}` - Calculate BLAKE2 checksums for multiple files: `b2sum {{filename1}} {{filename2}}` - Read a file of BLAKE2 sums and filenames and verify all files have matching checksums: `b2sum -c {{filename.b2}}` - Calculate the BLAKE2 checksum from `stdin`: `{{somecommand}} | b2sum`