SHA-256 vs. MD5 for Password Storage
SHA-256 is far more secure than MD5 in general, but neither is actually the recommended way to store passwords on its own — general-purpose hash functions like SHA-256 are designed to be fast, which is exactly the wrong property for password storage, since it lets an attacker who steals a password database try billions of guesses per second; purpose-built password-hashing algorithms like bcrypt or Argon2 are deliberately slow and incorporate salting, making large-scale guessing attacks far less practical.
This is a genuinely important distinction that even MD5-vs-SHA-256 comparisons often miss: the real issue for password storage isn't just which general-purpose hash is stronger.
Why speed is the wrong property for password hashing
As covered in the what-a-hash-function-does guide, SHA-256 is engineered to compute quickly, which is desirable for verifying file integrity or digital signatures — but for a stolen password database, that same speed lets an attacker test enormous numbers of guessed passwords per second against every hash in the file.
What salting adds regardless of which hash you use
Salting means adding a unique random value to each password before hashing it, so two identical passwords don't produce the identical hash — without a salt, an attacker can precompute a lookup table of common password hashes once and reuse it against every stolen database, which a unique salt per user defeats.