Antonov An-225 Mriya of Ukraine takes the crown of being the heaviest plane on Earth (285,000kg). Today, it is primarily deployed for commercial cargo transport.
Airbus A380-800 is a slight lighter at 277,000kg but no less a flying behemoth. It is the world's largest passenger airline. period. Airbus A380-800's usable floor space is 550 sq meters (5,920 sq ft), a staggering 40% more than the next largest airliner, the Boeing 747-8.
Stratolaunch. Third heaviest plane is Stratolaunch, a special plane (or a pair of planes) built to deliver payloads, such as satellites, into spatial orbits. It weights 226,796 kg without payload and has the longest wingspan of any aircraft at 117m.
Datasets on Aircrafts: