Yes, you can generally leave the airport during an international layover in 2026, provided you meet the entry requirements of the transit country and have enough time. You must pass through Immigration and Passport Control, which may require a transit visa or an electronic authorization (like an ESTA for the US or an ETA for the UK). Most experts recommend a layover of at least 8 to 10 hours to make exiting the airport worthwhile, as you must factor in deplaning, clearing customs, traveling to the city, and then returning 3 hours early to clear security again. Some hubs, like Doha, Singapore, and Istanbul, actively encourage this by offering free city tours or "stopover" programs for passengers with long waits, making the layover a "bonus" mini-vacation.