Cryptographic hash functions transform arbitrary input into a fixed-length digest — deterministic, one-way, and avalanche-sensitive (a single bit change in input causes roughly half the output bits to change). This tool computes the most common hash algorithms simultaneously so you can verify checksums, debug encoding pipelines, and choose the right algorithm for your use case.
MD5: 128-bit digest. Fast, widely used for non-security checksums and deduplication. Cryptographically broken (collision attacks practical). SHA-1: 160-bit digest. Also broken (SHAttered collision attack, 2017). SHA-256: 256-bit digest. Current standard for most security applications, used in HTTPS certificates, Bitcoin, and Git. SHA-512: 512-bit digest. Larger output, slightly slower on 32-bit systems, used where extra collision resistance is needed.
A tiny change in input (even flipping one bit) causes a completely different hash output — roughly half the bits change. This property ensures hash functions cannot be reversed or partially matched.
No. SHA-256 is fast by design — attackers can compute billions of guesses per second with a GPU. Password storage requires a slow, memory-hard function: bcrypt, Argon2, or scrypt with appropriate cost parameters.
The software provider publishes a hash (e.g. SHA-256) alongside the download. Download the file, hash it with this tool in File mode, and compare the result to the published hash. Any mismatch means the file is corrupt or tampered.
For non-password hashing (checksums, commitments, HMAC, digital signatures), yes — SHA-256 is secure and recommended. For passwords, use bcrypt/Argon2. For very high security contexts, SHA-384 or SHA-512 may be preferred.
See also the All Hashes tool, Bcrypt Generator, and HMAC generator.