SHA-256 vs SHA-512 — Which Hash Should You Use?
Comparing SHA-256 and SHA-512 for password hashing, file integrity, and digital signatures. Speed, security, and use-case recommendations.
SHA-256
Safe, fast, default choice for most applications.
SHA-512
More security margin, faster on 64-bit hardware.
Overview
Both SHA-256 and SHA-512 are members of the SHA-2 family, designed by the NSA and standardized by NIST. Both are secure. The choice between them is about performance and security margin, not about one being broken.
Side-by-side
| Feature | SHA-256 | SHA-512 |
|---|---|---|
| Output size | 256 bits / 32 bytes / 64 hex chars | 512 bits / 64 bytes / 128 hex chars |
| Internal block size | 32-bit operations | 64-bit operations |
| Speed on 32-bit CPU | Faster | Slower |
| Speed on 64-bit CPU | Fast | Often faster than SHA-256 |
| Collision resistance | 128 bits | 256 bits |
| Preimage resistance | 256 bits | 512 bits |
| Broken? | No (as of 2026) | No (as of 2026) |
| Bitcoin, Ethereum use | Yes | No |
| TLS certificates | Most common | Occasional |
| Password hashing | Only with KDF (PBKDF2, Argon2) | Only with KDF (PBKDF2, Argon2) |
Bottom line
Default to SHA-256 — it's everywhere, fast, and secure. Use SHA-512 when you need more security margin or are running exclusively on 64-bit hardware. Never use either bare hash for password storage — always use a proper KDF like Argon2id, bcrypt, or PBKDF2.
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Hash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text.