Is MD5 still safe to use?

Not for security. MD5 is cryptographically broken — attackers can deliberately create two different inputs with the same hash (a collision) in seconds. It is fine as a fast, non-security checksum to detect accidental file corruption, but never for signatures, certificates, or passwords.

What is the difference between MD5 and SHA-256?

MD5 produces a 128-bit (32 hex character) hash and is broken. SHA-256 produces a 256-bit (64 hex character) hash and is part of the SHA-2 family, which has no known practical collision attacks. SHA-256 is the modern default for integrity and security.

Should I hash passwords with SHA-256?

No — not on its own. SHA-256 is designed to be fast, which is exactly wrong for passwords because it lets attackers try billions of guesses per second. Use a slow, salted password hash like bcrypt, scrypt, or Argon2 instead.

What is a hash collision?

A collision is when two different inputs produce the same hash output. A secure hash makes finding collisions computationally infeasible. MD5's collision resistance is completely broken; SHA-256's is intact, which is why MD5 must not be used where collisions could be exploited.

Is MD5 Safe? MD5 vs SHA-256 Explained

MD5 has a split reputation: it is simultaneously one of the most widely used hash functions in the world and one of the most thoroughly broken. The truth is that it depends entirely on what you are using it for. Let us settle when MD5 is fine, when it is dangerous, and why SHA-256 is the modern default.

What a Hash Function Actually Does

A cryptographic hash turns any input — a word, a file, a gigabyte of data — into a fixed-length fingerprint. The same input always yields the same output, but you cannot reverse the output back into the input. A good hash also makes it infeasible to find two inputs that share the same fingerprint. That last property, collision resistance, is exactly where MD5 fails.

MD5 vs SHA-256 at a Glance

Property	MD5	SHA-256
Output size	128-bit (32 hex chars)	256-bit (64 hex chars)
Year published	1992	2001 (SHA-2 family)
Collision resistance	Broken (collisions in seconds)	Intact (no practical attack)
Safe for security?	No	Yes
Good for checksums?	Yes (non-adversarial)	Yes
Speed	Very fast	Fast

When MD5 Is Still Acceptable

MD5 is fast and produces a compact fingerprint, which keeps it useful for non-security checksums — verifying that a file downloaded without accidental corruption, deduplicating files, or generating cache keys. In these cases there is no attacker trying to forge a match, so a collision would only ever happen by astronomically unlikely chance.

When MD5 Is Dangerous

The moment an adversary could benefit from two inputs sharing a hash, MD5 must not be used. Real attacks have produced forged TLS certificates and malware that matches the checksum of legitimate software. Never use MD5 for:

Digital signatures or certificates
Verifying downloads where tampering is a threat
Password storage (broken on two counts — see below)
Any "proof" that data has not been altered by someone with an incentive to alter it

Never Hash Passwords With MD5 — or Plain SHA-256

This surprises people: even SHA-256 is the wrong tool for passwords. General-purpose hashes are designed to be fast, which lets attackers test billions of password guesses per second against a stolen database. Passwords need a deliberately slow, salted algorithm: bcrypt or scrypt (and Argon2). These add a per-user salt and a tunable work factor so each guess is expensive.

Try the Hashers

See the difference yourself: hash the same text with MD5 and SHA-256, and compare them to SHA-512 or the SHA-3 family. All hashing runs in your browser — nothing is uploaded.