Atlanta has been the world's busiest airport by passenger traffic since 1998, and by number of landings and take-offs every year since 2005 except 2014. Hartsfield–Jackson held its ranking as the world's busiest airport in 2012, both in passengers and number of flights, by accommodating 100 million passengers (more than 260,000 passengers daily) and 950,119 flights.
In 2017, it remained the busiest airport in the world with 104 million passengers.
Hartsfield–Jackson is the primary hub of Delta Air Lines, and is a focus city for low-cost carriersFrontier Airlines, Southwest Airlines, and Spirit Airlines. With just over 1,000 flights a day to 225 domestic and international destinations, the Delta hub is the world's largest hub. Delta Air Lines flew 75.4% of the airport's passengers in February 2016, Southwest flew 9.2%, and American Airlines flew 2.5%. In addition to hosting Delta's corporate headquarters, Hartsfield–Jackson is also the home of Delta's Technical Operations Center, which is the airline's primary maintenance, repair and overhaul arm.