MD4 Hash Generator

What is MD4?

MD4 returns 128 bits for any input: 16 raw bytes, or 32 hexadecimal characters. Hash typed text or uploaded files and the tool returns both.

Why anyone still computes it

MD4 is cryptographically broken, and more thoroughly than most. Practical collision attacks against it are old and cheap.

The reason it exists as a tool is compatibility, and nothing else. A handful of legacy protocols and file formats still encode MD4 values, and reproducing one is occasionally unavoidable when working with old systems. If a specification does not explicitly demand MD4, you do not want it.

Are there alternatives?

Everything. BLAKE3, SHA256, and SHA3 are all unbroken and no harder to use. For non-cryptographic integrity checks, CRC-32 and Adler-32 are faster and do not pretend to offer security.

MD5 is the closer relative and equally broken, so moving from MD4 to MD5 is not an upgrade worth making.

Fun facts and more info

MD4 is the ancestor of a whole line of hashes. The design ideas behind it fed into MD5, SHA-1, and the SHA-2 family, so the structure that was eventually broken here reappears, strengthened, in algorithms still in service. That shared lineage is a large part of why SHA3 was standardized on a completely different construction.

Use MD4 only when an existing format requires it. It must not be used for passwords, signatures, certificates, authentication, or integrity against deliberate modification.