This is our implementation of the famous MD5 algorithm, and presents an easy and highly secure way of verifying the integrity of files. Single-line text, multi-line text and file contents are all supported inputs. The resulting MD5 hash is displayed in a textbox for easy clipboard copying.

Software is often accompanied by an MD5 'hash' (or 'checksum'). This serves as a unique identifier for the contents of the file - if the file contents change then so does the MD5 hash, making it easy to verify the integrity of files.

The algorithm takes as input a message of arbitrary length and produces as output a 128 bit (16 byte) "fingerprint" of the input (also known as a "message digest", "checksum" or "hash"). It is conjectured that it is computationally infeasible to produce two messages having the same message digest, or to produce any message having a given prespecified target message digest. The MD5 algorithm was designed by Ron Rivest.