MD5 vs SHA-256: How to Choose a Hash Algorithm
WebTool Team · Published 2026-08-20 · Hashing / Security / MD5 / SHA256
Bottom line up front: use SHA-256 or stronger for any new system; MD5 is only acceptable as a fingerprint in non-security contexts; for password storage use bcrypt/argon2, not any raw hash. We offer online MD5, SHA, and HMAC calculators.
Comparison Table
| Algorithm | Digest length | Collision status | Current recommendation |
|---|---|---|---|
| MD5 | 128 bits (32 hex chars) | Practical collisions constructed (2004) | Non-security uses only |
| SHA-1 | 160 bits (40 hex chars) | Practically broken (SHAttered, 2017) | Legacy compatibility only |
| SHA-256 | 256 bits (64 hex chars) | Unbroken | Default choice |
| SHA-512 | 512 bits (128 hex chars) | Unbroken | When you need a longer digest |
Choosing by Use Case
- File integrity checks (guarding against transfer corruption): MD5 or SHA-256 both work — use whatever the other side provides.
- Digital signatures / certificates / blockchain: SHA-256 or stronger, no exceptions.
- API request signing (tamper-proofing + authentication): not a raw hash but HMAC — see the HMAC calculator.
- Password storage: none of the above! Use bcrypt, scrypt, or argon2 (slow hashing with salt).
Why "MD5 Decryption" Is a Myth
Hashing is a one-way function — no inverse operation exists mathematically. The so-called "MD5 decrypt" sites are really just rainbow tables: they precompute hashes for massive numbers of common strings and look them up. That's why salting passwords before hashing is table stakes — a salt makes every user's hash input unique and renders rainbow tables useless.
Last updated: 2026-08-20