The Seydlitz was a slight modified version of the previous Moltke  class battlecruisers with several improvements. since the previous battlecruisers had a very low bow height, causing bad seagoing capabilities, this was modified in the Seydlitz design. In addition with a longer hull the increased engine power gave the ship a higher top speed.

The most important improvement was a better armor protection. although armor sizes did not increase very much, the tighter internal subdivision of the ship made it possible that it survived heavy battle damage several times.

The Seydlitz took part in most battlecruiser operations - it lost two turrets during the battle at the Doggerbank and was the most damaged German warship at the battle of Jutland. With over 20 heavy artillery hits, the ship lost two gun turrets again and had a total of about 5400 t water in the ship. Despite this damage, it was still able to return to Germany under its own power - sailing backwards since the bow was only 2,5 meters above the sea level with all the water in the ship.

The final fate of the Seydlitz was the same as of most Hochseeflotte ships, it was scuttled at Scapa Flow and broken down between World War I and World War II.