The gray whale (Eschrichtius robustus) is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length of 14.9 meters (49 ft), a weight of 36 tonnes (40 short tons)

The humpback whale (Megaptera novaeangliae) is a species of baleen whale. One of the larger rorqual species, adults range in length from 12–16 metres (39–52 ft) and weigh approximately 36,000 kilograms (79,000 lb)

Humpback Whale is bigger than gray whale

And why u comparing this 2 animal ?