What is the difference between a Boeing 747 and a 777?

The Boeing 747 is the original “Jumbo Jet”. The basic design is a 4 engined commercial wide-body airliner, and it has the distinctive double-deck hump forward of mid-fuselage. The original design for the 747 was done in the 1960’s, and first service was in the early 70’s, but multiple variants have come and gone since then including freighters and “SP” special performance options for shorter haul, the latest version in passenger service is the Boeing 747-8i:

The Boeing 777 is a 2 engined commercial wide-body airliner, designed in the 1990’s and first in service in 1995 . The design of the “triple-seven” came about with development of higher efficiency turbofan engines which allowed long haul extended twin engine operations (ETOPS), to replace less efficient tri-engine long haul aircraft like the L-1011 and DC10. There are a number of variants including freighter options, the latest version in passenger service is the Boeing 777-300ER.

Basically everything; they’re entirely different aircraft created in different eras.

The 747 was created in the 1960s and produced starting in 1970, and basically created the idea of the “jumbo jet.” It was the first “wide-body” airliner, with two aisles instead of one, and due to the desire for cargo versions to have noses that could open, had its cockpit upstairs from the main deck, along with a lounge or a small number of seats. Like other long-range jets of its day, it had four engines. Depending on how many classes of seating were offered, it could carry between 350 and 550 passengers.

The 777 was created in the late 1980s and entered service in 1995, and was designed to fill the gap between the smaller 767 and larger 747. Although a 777-300 can be configured to seat 550 passengers, that’s really packing them in, so most configurations range between 300 and 450 passengers. A big difference is that the 777 only has two engines - although they’re huge ones - and costs less to operate than even the latest, most efficient 747. (It’s about one-third of a cent cheaper per seat, per mile - so an airline flying 450 passengers 5,000 miles saves $8,000 by using a 777 instead of a 747. The 777-200LR is also the longest-range airliner in the world, which is a selling point.

747s are still incredibly popular as freighters, but have really lost market to 777s on the passenger side of things. While just about everyone who was anyone flew 747-400s, many former 747-400 operators no longer fly 747s at all, and only 5 airlines (3 of them “major”) have ordered the latest greatest 747-8i for passenger service. Counting both passenger and freighter models, the 1,500th 747 was recently delivered - 45 years after the type entered service. Meanwhile, the 777 is increasingly popular, and 20 years after entry into service has over 1,800 orders and over 1,300 already delivered.

Due to shifting demand and changing route networks over time, airlines have worked to “right-size” their fleets, so that they have aircraft that can reach their desired destinations efficiently, with enough seats to more or less meet demand, but not drastically exceed it - nobody wants to fly half-empty.

This means that many airlines that formerly operated 747s now view the 777 as a more efficient alternative - with at least as much range - for routes that perhaps couldn’t justify using a 747. Similarly, many realized they lack the demand to even fill 777s, and have “downgauged” to slightly smaller aircraft such as the Airbus 340, Airbus 330, Boeing 787 and Boeing 767. A few feel they have the necessary demand to justify flying the higher-capacity Airbus 380 or the new 747-8i on a few routes, and the 777 on many routes.

As one example, Turkish Airlines has 21 777-300s in service, the largest aircraft it flies. It also has 51 Airbus 330s, and 4 Airbus 340s, for routes with less demand, and about twice as many short-haul planes (Boeing 737-700/800/900, Airbus 319/320/321) as it has long-haul. This fleet mix enables Turkish to offer flights to 110 countries, putting it far ahead of second-place Lufthansa, which flies to a mere 83 countries with a mix of Airbus 380, 747-400, 747-8i, Airbus 340, Airbus 330, and a short-haul flight transitioning away from 737s toward A319/320/321s. Lufthansa only uses 777s as freighters!

There’s more than one way to skin a cat in the airline business, but a lot of airlines view the 777 as a good way to skin one, nowadays.