Layover length and terminal changes matter
Whether you need a transit visa depends on the country, your layover length, and whether you change terminals or leave the airport transit zone. A short same-terminal layover may be visa-free, while a longer one or a terminal change may require a transit visa.
Your nationality and passport matter too
Transit visa rules vary by passport nationality. Indian passport holders face transit visa requirements in several major hubs — always check the transit rule for your specific passport and airport, not a general guide.
Plan connections with buffer time
If your connection needs a transit visa, allow extra time for the visa check and the transit process. Tight connections with a transit visa requirement are a common cause of missed flights.