Golden Gate Park is 2.9 times larger than Hyde Park, London.
Area: 4 km2 calculated
Golden Gate Park, located in San Francisco, California, United States, is a large urban park consisting of 1,017 acres of public grounds. Configured as a rectangle, it is similar in shape but 20 percent larger than Central Park in New York, to which it is often compared. Wikipedia
Area: 1 km2 calculated
Hyde Park is one of the largest parks in London, and one of the Royal Parks of London, famous for its Speakers' Corner. The park was the site of the Great Exhibition of 1851, for which the Crystal Palace was designed by Joseph Paxton. Wikipedia