MD4 Generator
Generate MD4 hashes online — free, instant, and fully private. This MD4 hash generator implements RFC 1320 in pure JavaScript: hash text, checksum files, run batch MD4 hashing line-by-line, compute NTLM hashes, or use HMAC-MD4. No other free online MD4 generator combines all five.
Text is encoded as UTF-8 before hashing, matching RFC 1320 byte semantics. Exact bytes are hashed — no trimming or line-ending normalization.
The file is read with the FileReader API and hashed in your browser's memory. Nothing is sent anywhere — verify in DevTools → Network.
NTLM = MD4(UTF-16LE(password)), unsalted — e.g. NTLM("password") = 8846f7eaee8fb117ad06bdd830b7586c. Identical passwords always give identical hashes, which is exactly why NTLM is weak. Provided for legacy auth interop and forensics; never paste a real production password into any browser tool.
RFC 2104 construction with MD4 and a 64-byte block size. Provided for legacy interop — a keyed wrapper does not make MD4 suitable for new systems; prefer HMAC-SHA-256.
Compares against the exact UTF-8 bytes of your text. If it does not match, check the other party's encoding and line endings first.
Why this MD4 generator?
📜 True RFC 1320 implementation
Not a server round-trip, not Web Crypto (browsers don't ship MD4). A from-scratch JavaScript MD4 engine — padding, three rounds, exact rotation schedule — that reproduces all 7 official RFC 1320 test vectors, self-checked on every page load.
🪟 NTLM hashes included
The only free MD4 generator with a dedicated NTLM mode: MD4 over UTF-16LE, exactly as Windows computes it. Essential for legacy auth debugging and forensic analysis.
📋 Batch MD4 hashing
Hash up to 200 strings at once, one per line, in hex or base64, and export the results as CSV. Ideal for checksumming datasets, test fixtures, or migration lists.
📁 File checksums
Compute the MD4 checksum of any file entirely client-side — handy when a legacy archive or protocol trace publishes MD4 checksums you must verify.
🔑 HMAC-MD4 included
The RFC 2104 keyed-hash construction with MD4 for interoperability with legacy systems that require it — alongside the plain MD4 generator in one page.
✅ Verify mode
Paste a published MD4 hash (hex or base64) and confirm your text reproduces it byte-for-byte — the fastest way to settle "is it the algorithm or the bytes?"
How to generate an MD4 hash
- Type or paste text into the Text tab — the MD4 digest appears instantly (no button needed).
- Pick the output format. Lowercase hex is the standard; UPPERCASE hex suits some legacy tools; base64 compacts the 16-byte digest to 24 characters.
- Copy or download. One click copies the hash; download saves it as a .txt file.
Need many at once? The Batch tab hashes up to 200 lines and exports CSV. Checking a Windows password hash? The NTLM tab computes MD4(UTF-16LE). Checking a download? The File tab checksums files without uploading them.
RFC 1320 test vectors self-checking…
Every correct MD4 implementation must reproduce these values from RFC 1320 Appendix A.5:
| Input | MD4 digest | Status |
|---|
Beware of typo drift: some sites republish these vectors with transcription errors. When in doubt, trust the RFC — or better, trust an engine that checks itself, like this one.
MD4 vs MD5 vs SHA-256
| Algorithm | Digest | Rounds | Security status |
|---|---|---|---|
| MD4 | 128-bit | 3 (1990) | Broken — collisions in seconds |
| MD5 | 128-bit | 4 (1992) | Broken — collisions practical |
| SHA-256 | 256-bit | 64 (2001) | Secure — current standard |
Rule of thumb: MD4 and MD5 are history lessons and legacy glue — MD4 lives on inside NTLM. Anything adversarial gets SHA-256 or better.
MD4 hash generator — FAQ
What is MD4?
MD4 (Message-Digest Algorithm 4) is a cryptographic hash function designed by Ronald Rivest in 1990 and published as RFC 1320. It produces a fixed 128-bit digest (32 hexadecimal characters) from any input, using three rounds of bit operations over 512-bit blocks. It is the direct predecessor of MD5 and the hash at the core of Windows NTLM authentication.
How do I generate an MD4 hash online?
Paste your text into the Text tab above — the MD4 digest is computed instantly as you type, entirely in your browser. Switch between lowercase hex, UPPERCASE hex and base64 output, copy with one click, or download the result. For many inputs use the Batch tab (one string per line, CSV export); to checksum a file, use the File tab.
Is MD4 secure?
No. MD4 is cryptographically broken: theoretical weaknesses were shown by Dobbertin in 1996 and practical collision attacks — two different inputs with the same hash, found in seconds — were demonstrated by Wang and others in 2005. Never use MD4 for passwords, digital signatures, or any security decision. This tool exists for legacy compatibility, non-adversarial checksums, protocol analysis, and education. For anything security-related, use SHA-256.
What is the MD4 hash of "abc"?
MD4("abc") = a448017aaf21d8525fc10ae87aa6729d, and MD4 of the empty string is 31d6cfe0d16ae931b73c59d7e0c089c0. Both come from the official test suite in RFC 1320 Appendix A.5 (recomputed and verified by this page’s self-check). The test-vectors table below re-verifies all 7 official vectors live against this page’s engine every time it loads.
What is NTLM and how does it relate to MD4?
An NTLM hash is simply MD4 computed over the UTF-16LE (little-endian) encoding of a password — no salt, no iterations. Windows has used it for authentication since Windows NT, which is why MD4 still matters in legacy and forensics work. The NTLM tab on this page computes exactly that: type a password and you get the same value Windows stores. Because it is unsalted, identical passwords always produce identical NTLM hashes.
What is the difference between MD4 and MD5?
MD5 (1992) is MD4's direct successor: both produce 128-bit digests, but MD5 adds a fourth round, stronger message scheduling, and different constants, making it considerably stronger than MD4 — yet MD5 is also cryptographically broken (practical collisions since 2004). Neither should be used for security today. MD4 survives in NTLM, old protocols, and teaching material; MD5 lingers in legacy checksums.
Can I compute the MD4 checksum of a file?
Yes. Open the File tab, choose any file, and its MD4 checksum is computed locally with the FileReader API — the file never leaves your device and is never uploaded. This is useful when an old software archive, legacy system, or protocol trace publishes MD4 checksums you need to verify.
Why does another site show a different MD4 hash for the same text?
Almost always it is a bytes problem, not an algorithm problem: the sites hashed different bytes. Common causes are different text encodings (UTF-8 vs UTF-16), line endings (LF vs CRLF), or invisible trailing whitespace/newlines. This tool hashes the exact UTF-8 bytes of what you type — no trimming, no normalization. A second cause is typo drift: some sites republish the RFC 1320 test vectors with transcription errors. A correct implementation must reproduce all 7 vectors in RFC 1320 Appendix A.5, which this page self-checks on every load.
Related security tools
Identify an unknown hash with our Hash Identifier (it recognizes MD4 among 300+ types), verify file integrity with the File Checksum Verifier, generate keyed hashes with the HMAC Generator, or compute SHA-1 hashes.
Free tool by NRTechStudio