The male herring gull is 60–67 cm long and weighs 1,050–1,525 grams, while the female is 55–62 cm and weighs 710–1,100 grams. The wingspan can range from 125 to 155 cm. Among standard measurements, the wing chord is 38 to 48 cm , the bill is 4.4 to 6.5 cm and the tarsus is 5.3 to 7.5 cm. Adults in breeding plumage have a light grey back and upper wings and white head and underparts. The wingtips are black with white spots known as "mirrors". The bill is yellow with a red spot and a ring of bare yellow skin is seen around the pale eye. The legs are normally pink at all ages. Juveniles are mottled brown with a dark bar at the tip of the tail

Herring gulls are noisy, gregarious birds with distinctive vocalisations. Their loud, laughing call is particularly well known, and is often seen as a symbol of the seaside in countries such as the United Kingdom.

It can only catch slow creatures, like small crabs, which it often drops from some altitude to crack them open. The bird has little real power in its jaws while biting, but it may "stab" with better strength. Fish on land, eggs of other birds, and helpless chicks of smaller ducks. It is then far more successful as a scavenger