Whether you need a visa for a layover depends on your nationality, your destination, and whether you plan to exit the airport's "International Transit Zone." In many global hubs like Singapore (Changi), Dubai (DXB), or Amsterdam (Schiphol), most passengers do not need a visa if they stay "airside" and have a confirmed onward ticket within 24 hours. However, some countries, most notably the United States, Canada, and Australia, require almost all transiting passengers to have a "Transit Visa" (or an eTA/ESTA) even if they never leave the airport. In 2026, many European countries also require a "Schengen Airport Transit Visa" (Type A) for citizens of certain nations. If your layover involves "Self-Transfer"—where you must pick up your luggage, clear customs, and re-check in at a different terminal—you will almost certainly need a full tourist or transit visa because you are legally "entering" the country. Always check the specific "Transit" section of the embassy website for your layover country at least two weeks before you fly, as "indirect" flights through a third country are one of the most common ways travelers get denied boarding at the gate.