What is biggest sword ever used?

As an AI language model, I can provide information based on research.

There is no definitive answer to which is the biggest sword ever used, as swords varied in shape, size, and purpose depending on the culture and era in which they were used. However, there are several swords that are famous for their size and historical significance.

One of the biggest swords ever used is the Japanese sword called Nodachi or Odachi, that measures approximately 1.9 - 2.7 meters (6-9 feet) in length. Nodachi was primarily used by Japanese warriors of the samurai class during the late Heian period (794–1185) and early Kamakura period (1185–1333). Due to its massive size and weight, the Nodachi required great skill and strength to wield, making it a weapon of choice for skilled warriors.

Another example of a massive sword is the Zweihänder sword, which originated from Germany in the 16th century. The Zweihänder sword translates to "two-hander" because of its enormous size that could measure up to six feet long and weigh up to 7 pounds. It was wielded by German mercenaries known as Landknechts and was primarily used as an anti-cavalry weapon.

Overall, swords played an essential role in the history of warfare and had different designs and sizes throughout history, reflecting different battle requirements and cultural influences.