The Tiger differed from earlier German tanks principally in its size; although the general design and layout were broadly similar to the previous heavy tank, the Panzer IV, the Tiger weighed more than twice as much. This was due to its substantially thicker armor, the larger main gun, and the consequently greater volume of fuel and ammunition storage, larger engine, and more solidly-built transmission and suspension. The Tiger I had front armor up to 100 mm thick, as opposed to the 80 mm front armor of contemporary models of the Panzer IV, with 80 mm on the sides and back. The armor, especially in the front, was very effective at stopping anti-tank rounds of most of the WWII tank guns at common engagement distances. At closer ranges and on the sides, the tank was more vulnerable. Its roof armor was 25 mm or 40 mm, similar to most medium tanks of the day.

The StuG IV is a slightly modified Sturmgeschütz III superstructure mounted on a Panzer IV chassis. Around 1100 were built starting in 1943. The StuG IV was known as a very effective tank killers, especially on the Eastern Front.