Calculate SHA-1, SHA-256 and SHA-512 checksum length and verification time for a file.
SHA-256 and SHA-512 are members of the SHA-2 family of cryptographic hash functions producing fixed-length digests — 256 bits (64 hex characters, 32 bytes) and 512 bits (128 hex characters, 64 bytes) respectively — regardless of input size. This calculator shows the expected output length and format that `sha256sum`/`sha512sum` would produce; the displayed digest is a deterministic but non-cryptographic illustrative placeholder (this page runs client-side without a bundled crypto library), not a substitute for the real command when verifying file integrity.
Output length
hex_chars = output_bits / 4; bytes = output_bits / 8
`sha256sum filename` prints the 64-character hex digest followed by the filename. For SHA-512, use `sha512sum filename` (128 hex characters). Both read the file's actual bytes — always use the real command-line tool, not an illustrative web calculator, when verifying downloaded file integrity.
SHA-512 operates on 64-bit words, which map directly onto the native word size of modern 64-bit processors, so despite producing a longer digest it can outperform SHA-256 (which uses 32-bit words) per byte processed on such hardware.
Yes — SHA-256 and SHA-512 have no known practical collision or preimage attacks and remain the standard choice for file integrity checks, TLS certificates, and package signing as of today. MD5 and SHA-1, by contrast, are considered broken for security purposes.