SHA-256 / SHA-512 Generator

What is SHA-2?

SHA-256 and SHA-512 are members of the SHA-2 hash function family, designed by the NSA and standardized by NIST in FIPS 180-4. A SHA-2 hash function takes input of any size and produces a fixed-length digest: 256 bits (64 hex characters) for SHA-256, or 512 bits (128 hex characters) for SHA-512. Both are deterministic, one-way, and collision-resistant — flipping a single input bit produces a completely different output.

This SHA-256 calculator is free and runs entirely client-side. It uses your browser's native crypto.subtle.digest API, which is the same primitive used by TLS, JWTs, andgit. Nothing is uploaded, logged, or stored.

SHA-256 vs SHA-512 — which should you use?

Both are considered cryptographically secure today, so the choice is mostly about output size and performance. SHA-256 produces a shorter 64-character digest that is more compact in databases, URLs, and logs — pick it for content addressing, ETags, JWT signing (HS256), file checksums, and most general-purpose fingerprinting. SHA-512 is internally optimized for 64-bit CPUs and is often faster on server-class hardware; it's a good choice when you want a longer digest for HMAC keys or when you need extra collision margin (HS512, certificate fingerprints). When in doubt, use SHA-256.

When to use a SHA-2 hash function

Reach for SHA-256 or SHA-512 whenever you need a tamper-evident fingerprint of data: verifying downloads, signing tokens, indexing content, or building HMACs. Do notuse raw SHA-2 to store user passwords — it's far too fast. Use a password-hashing function like bcrypt, scrypt, or Argon2 instead.