As of March 2025, Booking Holdings recorded the highest market cap among the selected online travel companies worldwide. As of that month, Booking Holdings – the leading online travel agency (OTA) worldwide by revenue – recorded a market cap of over 146 billion U.S. dollars. Airbnb and Trip.com Group followed in the ranking, with a market cap of roughly 79.1 billion and 43.2 billion U.S. dollars, respectively. What are the most visited travel and tourism websites? Booking.com, Booking Holdings' flagship brand, ranked as the most visited travel and tourism website worldwide in 2025, with over 560 million visits, ranking ahead of tripadvisor.com and airbnb.com. When looking at the geographical distribution of booking.com's visits, the United States accounted for the highest traffic, followed by Germany and the United Kingdom. How big is the online travel market? As shown by the travel and tourism's global revenue breakdown by sales channel, online transactions play a fundamental role in this market, representing over two-thirds of total travel and tourism's revenue in 2024. That year, the online travel market size worldwide was estimated at over 640 billion U.S. dollars, recording an annual increase.