MD4 Hash Generator and Lookup
Understanding MD4
MD4 is a legacy hash function that produces a 128-bit digest, normally displayed as 32 hexadecimal characters. It is cryptographically broken and should not be selected for new security systems.
Digest size128 bits
Common format32 hexadecimal characters
Generation and database lookup
This tool generates MD4 digests and searches our indexed corpus for a matching plaintext. A database lookup does not mathematically reverse MD4; it can only recover text that was previously indexed.
Security guidance
For new systems, choose a modern function suited to the task. Passwords should use Argon2id, scrypt or bcrypt with a unique salt and an appropriate work factor. NTLM also relies on MD4, but hashes the UTF-16LE representation of the password.
FAQ
How long is an MD4 hash?
An MD4 digest is 128 bits long and is usually written as 32 hexadecimal characters.
Can MD4 really be decrypted?
No. This page performs a lookup in an indexed corpus; it cannot derive an unknown plaintext from the digest alone.
Is MD4 still secure?
No. MD4 has major cryptographic weaknesses and should not be used in new applications.
Practical notes
MD4 is a broken historical hash. It remains useful for recognizing legacy formats, notably the NTLM construction.
Length128 bits / 32 hex
StatusObsolete
RelatedBasis of NTLM
Frequently asked questions
Are MD4 and MD5 compatible?
No. Both produce 32 hexadecimal characters, but their calculations and outputs differ.
Why does MD4 still appear?
Legacy systems and NTLM still use it, which explains its analytical relevance.
Should it be used in a new application?
No. Use a modern primitive suited to the task.