which sea beach is the world largest beach?

Answer 1

"Cox's Bazar in Bangladesh is one of the world's longest natural sea beach (120 km) including mud flats." [1]

"The 120 km (75 mile) unbroken stretch of beach here [Cox's Bazar] is the world's longest..." [2]

There are several beaches which are claimed to be the "World's longest", including Cox's Bazar, Bangladesh (120kms), Fraser Island beach, 90 Mile Beach in Australia and 90 Mile Beach in New Zealand and Long Beach, Washington (which is about 30km). Wasaga Beach, Ontario on Georgian Bay claims to have the world's longest freshwater beach. [3]

Answer 2

Cox's Bazar of Bangladesh is the world largest beach.