MD5 Reverse Lookup

How does MD5 reverse lookup work?

MD5 is a one-way hash function — it cannot be mathematically reversed. What reverse lookup tools do is compare your hash against a pre-computed database of millions of known hash-to-plaintext pairs (called a rainbow table). If your hash exists in the database, the original string is returned.

Hashes generated from complex, unique strings are unlikely to appear in any rainbow table and cannot be reversed by this method.