mzCloud is a new concept of mass spectral database that aims to assist analysts in identifying compounds even when they are not present in the library. mzCloud features a freely searchable collection of high resolution/accurate mass spectra using a novel spectra correlation algorithm. mzCloud represents a monumental, community-based effort that aims to collect a comprehensive library of high quality spectral trees to improve the structure elucidation of unknowns in fields such as metabolomics, toxicology, environmental sciences, and the food and beverages' sector.