Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 cryptographic hashes from text or file. HMAC signing supported. Everything runs in your browser — no data uploaded.
A cryptographic hash function takes an input of any length and produces a fixed-size output (the hash or digest). It is deterministic (same input always gives same output), one-way (you cannot reverse the hash to recover the input), and collision-resistant (it is computationally infeasible to find two different inputs with the same hash).
SHA-256 is the most widely used hash function today. It produces a 256-bit (64 hex char) digest and is used in SSL/TLS certificates, Bitcoin, Git, and most modern password hashing schemes.
MD5 and SHA-1 are cryptographically broken — collision attacks are practical. They are still useful for non-security checksums (file integrity, cache keys) but must never be used for passwords or signatures.
HMAC (Hash-based Message Authentication Code) uses a secret key with a hash function to produce a tamper-proof signature. Used in API authentication (AWS, Stripe webhook verification) and JWT signatures.
Hex encoding uses two characters per byte (0–9, a–f). Base64 uses ~1.33 bytes per byte and is more compact. Hex is more human-readable; Base64 is preferred in HTTP headers and JWT.