The victims included 59 men, eight women, and four children, including a baby.
The four men convicted included one Afghan and three Bulgarians. Ten others, including nine from Bulgaria, were given shorter sentences of three to twelve years.
The court said they were guilty of “aggravated murder with particular cruelty” after a year-long trial in the town of Kecskemét, central Hungary.
The people-smuggling gang dumped the truck with the corpses at the side of an Austrian motorway.
The court heard the prosecution allege that as the truck made its way from the Hungarian-Serbian border towards Austria, the smugglers ignored the cries of the migrants who banged on the sides of the lorry and shouted.
Austrian police then found the bodies piled on top of each other inside. Investigations found they had been dead for two days.
Most of the victims were from Afghanistan, Iraq and Syria.
“The prosecution appeals and asks for heavier sentences,” prosecutor Gabor Schmidt told a packed courtroom.
The deaths shocked Europe as it struggled to cope with a massive influx of migrants. It was the worst incident of its kind on the Balkan route taken by hundreds of thousands fleeing war and poverty in the Middle East, Africa and Asia.
The suspects denied knowing their human cargo was dying, but the evidence showed otherwise.
The alleged ringleader, Samsoor Lahoo, told the court in a final statement that he “had not wanted anyone’s death.”
But police intercepted phone calls between the group, which revealed Lahoo had ordered the truck drivers not to open the doors.
One of the calls showed Lahoo had said: “Let them die instead. That’s an order... If they die, let him dump them in a forest in Germany.”
But the alleged ringleader told the court they were simply “thoughtless remarks.”