SHA-256 vs SHA-512 — Which Should You Use?
SHA-256 and SHA-512 are the two workhorses of the SHA-2 family. They share the same design philosophy and both are cryptographically secure, but they produce digests of different sizes and run on different word widths. Neither is 'better' in the abstract. Which one fits depends on the protocol you're matching and the platform you're on.
Use SHA-256 when
- You need to match an existing spec or protocol. TLS, certificates, and most checksums default to SHA-256.
- You want a compact 32-byte digest (64 hex chars) that's easy to embed, store, and compare.
- You're on a 32-bit platform or a constrained device where the smaller word width is a natural fit.
- 256 bits of security is already beyond brute-force reach, which it is for all practical purposes today.
Use SHA-512 when
- You need the larger 64-byte digest (128 hex chars), a common choice for integrity checks on large files.
- You're on a modern 64-bit processor, where SHA-512's 64-bit operations are typically faster than SHA-256.
- Your spec or hash chain explicitly calls for SHA-512, so matching it matters more than the size.
- You want the extra headroom for future-proofing against advances in cryptanalysis.
Side by side
| SHA-256 Hash Generator | SHA-512 Hash Generator | |
|---|---|---|
| Family | SHA-2 | SHA-2 |
| Digest size | 256 bits · 32 bytes | 512 bits · 64 bytes |
| Hex length | 64 chars | 128 chars |
| Base64 length | 44 chars | 88 chars |
| Word width | 32-bit words | 64-bit words |
| Fastest on | 32-bit platforms | 64-bit platforms |
| Security level | Collision-safe in practice | Collision-safe with more headroom |
| Where it runs | Browser, no upload | Browser, no upload |
Both are checksums, not password functions. Their speed is a strength for integrity and a weakness against brute force. Neither tool uploads your input; hashing happens entirely in the browser via the Web Crypto API.
Choose SHA-256 when you need to match an existing standard. It's the default everywhere from TLS to common checksums. Choose SHA-512 when the protocol calls for it, when you're on 64-bit hardware and want the larger digest, or when you want maximum headroom on file-integrity checks. For either, remember: a fast hash is for integrity, not passwords. Reach for bcrypt when security against guessing is the job.