The Web site and service was launched on 19 January 2013, by Kim Dotcom, together with chief technical officer, director, and co-founder Mathias Ortmann, chief marketing officer Finn Batato and Bram van der Kolk as a successor to Megaupload, which was then seized by the United States Department of Justice a year prior.

Data on MEGA services are end-to-end encrypted client-side using the AES algorithm. Since MEGA does not know the encryption keys to uploaded files, they cannot decrypt and view the content. Therefore, they cannot be responsible for the contents of uploaded files. By encrypting files MEGA can work with a larger number of data hosting companies around the world, decreasing the likelihood of a Megaupload-style seizure of servers by one government. MEGA also uses CloudRAID technology, which means files are split into roughly equal-sized parts and stored in different countries. They also store another part in yet another country recording whether the number of "1" bits at a certain position within all parts is even or odd. This means that users can reconstruct data even when one of the parts is unavailable.

Mega offers cloud based storage that allows individuals to backup, save and store files, photos, and videos and access them from a variety of platforms via mobile apps and web browsers. Additionally, Mega also supports secure messaging and sharing of files within the application.