MD4 Hash Generator
Turn any text into its 32-character MD4 hash instantly.
How to use the MD4 Hash Generator
- Type or paste your text in the box.
- The MD4 hash appears as you type.
- Click Copy to grab the result.
About the MD4 Hash Generator
MD4 (Message Digest 4) was designed by Ronald Rivest in 1990 and produces a 128-bit digest, written as 32 hexadecimal characters. Its real importance is historical: MD4 was the template that MD5 and SHA-1 were both built from. The whole lineage of fast, round-based, Merkle–Damgård hashes that dominated the 1990s and 2000s traces back to this one design — which also means they inherited the weaknesses that eventually sank all of them.
MD4 is thoroughly broken. It is not “weakening” or “deprecated” — collisions can be found essentially instantly on ordinary hardware, so two different inputs producing the same MD4 hash is a trivial exercise rather than a research result. Do not use MD4 for passwords, signatures, integrity checks, or anything where someone might benefit from forging a match. There is no cost to using a modern hash instead: SHA-256 for fingerprints, bcrypt for passwords.
So why does MD4 still ship in every crypto library? Because of Windows. The NTLM password hash is, at its core, MD4 applied to the password encoded as UTF-16LE — no salt, no iteration count, nothing to slow an attacker down. That single dependency keeps MD4 alive across enterprise networks and makes it a routine sight in penetration testing and password-recovery work, which is where most people hashing MD4 today actually encounter it.
Frequently asked questions
Can I decrypt or reverse an MD4 hash?
No. Hashing is one-way — the original text is not inside the hash. “MD4 decrypters” are lookup tables of previously hashed words, and because MD4 is fast and unsalted those tables are devastatingly effective, which is exactly why MD4 must not protect anything.
What is the connection between MD4 and NTLM?
The NTLM hash is MD4 of the password encoded in UTF-16LE. If you hash a password here as UTF-8 you will not get the NTLM value — use our NTLM hash generator, which applies the correct encoding first.
Why is my MD4 hash always 32 characters?
MD4 always outputs 128 bits, and each hex character represents 4 bits, so every MD4 hash is exactly 32 characters no matter how long the input is.
Is MD4 safe for anything?
Not for security. Collisions are instant, so it fails any use where someone might try to fool you. It survives only in legacy protocols like NTLM that cannot easily be changed, and as a non-adversarial checksum in old software.
Is my text sent anywhere?
Your text is sent to our server to be hashed, because browsers cannot compute MD4. It is hashed and immediately discarded — never logged, never stored.