The World Record of ‘heaviest jet plane’ has been achieved by AN-225 from Russia.

Antonov or AN-225 is the world’s heaviest jet plane. It was designed for the Soviet space program. AN-225 is able to airlift heavy and oversize freight up to 250,000 kg (550,000 lb) internally or 200,000 kg (440,000 lb) on the upper fuselage.