The ranking was based on a survey that assessed passengers' experiences across multiple factors, including waiting times, queuing systems, priority lanes, e-gate efficiency, and the courtesy and effectiveness of immigration staff.
Changi Airport upholds high hygiene standards with regular cleaning and disinfection, along with the use of advanced cleaning technologies like autonomous cleaning robots.
In addition, the airport emphasizes environmental sustainability by utilizing cleaner energy, reducing waste, and optimizing water consumption.
This year, Changi also regained its title as the world's best airport for 2025, after losing it to Qatar's Hamad International Airport last year.
The 2025 World's Cleanest Airports list is divided into two categories: one for all airports and another for airports with fewer than 25 million passengers annually.
Tokyo Haneda in Japan was voted the cleanest of all airports while Bahrain International Airport topped the list for airports serving up to 25 million passengers annually.