MD5.cc is an online MD5 lookup/cracking, MD5 decryption and encryption tool built around a hash lookup database. The source states that MD5 is a globally public encryption algorithm: regardless of the input length, it generates a 32-character hexadecimal string, called a hash or ciphertext. For example, `123456` becomes `e10adc3949ba59abbe56e057f20f883e` after encryption.

The source explains that this algorithm is one-way and irreversible, and it is usually not possible to find the original word from an MD5 hash. However, by exhaustively combining characters, a large one-to-one plaintext/ciphertext query database can be created to maximize the chance of recovering the original word.

Available site entries include free MD5 decryption, batch decryption, decryption range, articles, encryption, and QQ one-click login. The source material does not provide a self-hosted version, deployment steps, or resource requirements, so it is better evaluated as an online service.