Boston is 3.4 times larger than Jersey City, New Jersey.
Area: 129 km2 calculated
Boston is the capital and largest city of the Commonwealth of Massachusetts in the United States. Boston also serves as county seat of Suffolk County. Wikipedia
Area: 38 km2 calculated
Jersey City is the seat of Hudson County, New Jersey. As of the 2010 United States Census, the population of Jersey City was 247,597, making it the second-most populous city in New Jersey, after Newark. Wikipedia