Hash Generator

A hash is a fixed-length string produced by a one-way mathematical function. The same input always produces the same hash, but you cannot reverse a hash back to the original input.

For security-sensitive uses, prefer SHA-256, SHA-512, SHA3-256, or BLAKE2b. MD5 and SHA-1 are cryptographically broken and should only be used for checksums, not passwords or digital signatures.

SHA-2 (SHA-256/SHA-512) remains secure and is the default choice for most applications — it is ubiquitous, fast in hardware, and has no known practical weaknesses. SHA-3 (SHA3-256/SHA3-512) uses an entirely different internal construction (the Keccak sponge) and is a good pick when you want cryptographic diversity against a future SHA-2 break, or when a protocol specifically mandates it. The two produce different digests for the same input and are not interchangeable.

BLAKE2b-512 is a modern hash function that is typically faster than SHA-2 and SHA-3 in pure software while offering comparable security. It is a good pick for content-addressable storage, deduplication, and file fingerprinting where throughput matters. Note that BLAKE2 has a built-in keyed mode that is the idiomatic way to authenticate messages with it; HMAC-BLAKE2b works here but is rarely seen in practice.

No. General-purpose hashes are too fast for password hashing. Use bcrypt, Argon2, or scrypt instead — they are specifically designed to resist brute-force attacks.

Hash functions are deterministic — identical inputs always produce identical outputs, regardless of which tool computed them.