The Whopper is the signature sandwich and an associated product line sold by international fast food restaurant chain Burger King and its Australian franchise Hungry Jack's. Introduced in 1957, the sandwich has undergone several reformulations such as portion resizing and bread changes. The hamburger is well known in the fast food industry, with Burger King billing itself as "the Home of the Whopper" in its advertising, signage, and in its concept store, the BK Whopper Bar.