The 747-8 is offered in two main variants: the 747-8 Intercontinental (747-8I) for passengers and the 747-8 Freighter (747-8F) for cargo. The first 747-8F performed the model's maiden flight on February 8, 2010, with the 747-8I following on March 20, 2011. Delivery of the first freighter aircraft occurred in October 2011 and the passenger model began deliveries in 2012. As of July 2017, confirmed orders for the 747-8 total 133: 88 of the freighter version, and 45 of the passenger version.
Boeing had considered larger-capacity versions of the 747 several times during the 1990s and 2000s. The 747-500X and -600X, proposed at the 1996 Farnborough Airshow, would have stretched the 747 and used a 777-derived wing, but did not attract enough interest to enter development. In 2000, Boeing offered the 747X and 747X Stretch derivatives as alternatives to the Airbus A3XX. This was a more modest proposal than the previous 500X and 600X. The 747X would increase the 747's wingspan to 229 ft (69.8 m) by adding a segment at the root. The 747X was to carry 430 passengers up to 8,700 nmi (16,100 km). The 747X Stretch would be extended to 263 ft (80.2 m) long, allowing it to carry 500 passengers up to 7,800 nmi (14,400 km). However, the 747X family was unable to attract enough interest to enter production. Some of the ideas developed for the 747X were used on the 747-400ER.
After the 747X program, Boeing continued to study improvements to the 747. The 747-400XQLR (Quiet Long Range) was meant to have an increased range of 7,980 nmi (14,780 km), with better fuel efficiency and reduced noise. Changes studied included raked wingtips similar to those used on the 767-400ER and a 'sawtooth' engine nacelle for noise reduction. Although the 747-400XQLR did not move to production, many of its features were used for the 747 Advanced.
In early 2004, Boeing announced tentative plans for the 747 Advanced that were eventually adopted. Similar in nature to the 747X, the stretched 747 Advanced used technology from the Boeing 787 Dreamliner to modernize the design and its systems. On November 14, 2005, Boeing announced that it was launching the 747 Advanced as the "Boeing 747-8".
The 747-8 was designed to be the first lengthened 747 to go into production. The 747-8 and shortened 747SP are the only 747 variants with a fuselage of modified length. The 747-8 was intended to use the same engine and cockpit technology as that of the 787, including the General Electric GEnx turbofan and partial fly-by-wire. Boeing said that the new design would be quieter, more economical, and more environmentally friendly than previous versions of the 747. As a derivative of the already-common 747-400, the 747-8 has the economic benefit of similar training and interchangeable parts. Boeing firmed the 747-8 Freighter's configuration in October 2006.
The 747-8, as the current new development of Boeing's largest airliner, is notably in direct competition on long-haul routes with the Airbus A380, a full-length double-deck aircraft now in service. For airlines seeking very large passenger airliners, the two have been pitched as competitors on various occasions. Boeing states that the 747-8 is more than 10 percent lighter per seat and is to consume 11 percent less fuel per passenger than the A380, translating into a trip-cost reduction of 21 percent and a seat-mile cost reduction of over 6 percent.
Production of the first 747-8 Freighter began in Everett in early August 2008. On November 14, 2008, Boeing announced a delay to the 747-8 program, citing limited availability of engineering resources within Boeing, design changes, and the recent strike by factory workers. On July 21, 2009, Boeing released a photograph of the first cargo airplane, its fuselage and main wing assembled.
In February 2009, only one airline customer (Lufthansa) had ordered the 747-8I passenger model, and Boeing announced it was reassessing the 747-8 project. Chief executive Jim McNerney stated that continuation of the project was not a foregone conclusion. The company was assessing various options.
In October 2009, Boeing announced that it had delayed the first flight on the 747-8 until the first quarter of 2010 and delayed 747-8I delivery. The company took a US$1-billion charge against its earnings for this delay. In response, launch customer Cargolux stated it still intended to take delivery of the thirteen freighters it had ordered; Lufthansa confirmed its commitment to the passenger version. On November 12, 2009, Boeing announced that Cargolux's first airplane was fully assembled and entering the Everett plant's paint shop. It was to undergo flight testing prior to delivery.
On December 4, 2009, Korean Air became the second airline customer for the 8I passenger model, with an order for five airliners. On January 8, 2010, Guggenheim Aviation Partners (GAP) announced the reduction of its 8F order from four to two aircraft. In March 2011, Korean Air converted options into a firm order for two additional 8 freighters. It received its first -8I in late August 2015.