MD5 Hash Converter — Free Online MD5 Calculator
Convert any text into its MD5 hash value instantly and for free, right in your browser — nothing is sent to a server. Handy for file integrity checks, but not recommended for security due to proven collision attacks.
Tips
- MD5 is a 128-bit hash function designed by Ronald Rivest in 1991. A collision attack (producing the same hash from different inputs) was demonstrated in 2004, making it unsuitable for any security-sensitive use.
- MD5 is still widely used for file integrity checks — comparing the MD5 value published by a distributor with the one you calculate locally lets you detect accidental corruption (not malicious tampering).
- Using MD5 to store passwords is extremely dangerous. Modern GPUs can compute MD5 billions of times per second, cracking short passwords almost instantly.
- MD5 always outputs 128 bits (32 hexadecimal characters), regardless of the length of the input.
- For storing passwords, use dedicated algorithms like BCrypt or Argon2 that are intentionally slow.
FAQ
Side Note — The Inventor of MD5 and the Trajectory of a "Broken" Algorithm
MD5 (Message Digest Algorithm 5) was designed in 1991 by cryptographer Ronald Rivest (the "R" in RSA). It was widely adopted as a secure hash function, but design weaknesses were flagged in 1996, and in 2004 Chinese cryptographer Xiaoyun Wang and colleagues demonstrated a successful collision attack, sealing its retirement from security use.
In 2008, researchers reported the creation of a fraudulent SSL certificate exploiting MD5 collisions — forging a certificate with the same MD5 hash as a legitimate CA signature to enable man-in-the-middle attacks. This prompted major browsers and CAs to phase out MD5 in certificates entirely.
Today, MD5 survives primarily in non-security checksums. Verifying that a large file arrived intact after transfer — detecting accidental corruption rather than deliberate tampering — is a use case where MD5 still works perfectly well.