Hash Generator

What is a cryptographic hash?

A hash function maps input of any size to a fixed-length fingerprint: MD5 produces 128 bits (32 hex characters), SHA-256 produces 256 bits (64 hex characters). The same input always yields the same hash, while even a one-character change produces a completely different one — which is why hashes are used for checksums, cache keys, data deduplication, integrity verification and (with salt and a slow KDF) password storage.

Which algorithm should I use?

SHA-256 is the safe default for anything security-related — collision attacks against MD5 and SHA-1 are practical, so both are considered broken for signatures and certificates. MD5 and SHA-1 remain fine for non-security uses: verifying a download against a published checksum, generating cache keys, or spotting accidental corruption. For storing passwords, don't use any plain hash — use bcrypt, scrypt or Argon2.

FAQ

Can I reverse a hash to get the original text?

No — hashing is one-way. "Decrypting" MD5 sites are just lookup tables of precomputed hashes for common strings, which is exactly why unsalted password hashes are dangerous.

Why does the same text give a different hash on another site?

Usually a trailing newline or different character encoding. This tool hashes exactly what you type as UTF-8 with no added newline — equivalent to printf 'text' | sha256sum rather than echo, which appends \n.

Is my text uploaded to a server?

No. SHA hashes are computed with the browser's built-in WebCrypto API and MD5 with a compact implementation verified against the RFC 1321 test vectors — all locally.