MD4 File Hash
Calculate a legacy MD4 file hash or HMAC from a local file or URL without uploading local files. Read more
What is MD4?
MD4 is a legacy 128-bit message digest documented in RFC 1320. This calculator hashes raw file bytes for compatibility with old checksums and formats. RFC 6150 classifies MD4 as Historic because attacks have made it inappropriate for collision-resistant applications.
How to use this file hash calculator
Choose a local file or URL and result format. Leave HMAC disabled for a plain MD4 field, or enable it only for a legacy keyed value. Local file bytes and keys stay in the browser; URL access depends on CORS.
Result example
A file containing exactly abc produces a448017aaf21d8525fc10ae87aa6729d in Hex. Filename and metadata are excluded from the calculation.
Important limitations
MD4 collisions can be constructed, so MD4 is not suitable for adversarial file verification, signatures, or new authentication systems. Use a modern digest supplied by the publisher whenever one is available.
Frequently asked questions
Why does my result differ from another tool?
Confirm both tools process identical raw bytes and use the same MD4 or HMAC-MD4 mode. HMAC keys must match byte for byte.
Can I use the result to verify a download?
It can compare legacy MD4 data, but should not be introduced as a new checksum. For encoded text, use the MD4 calculator.
