Avengers: Endgame (2019) and its predecessor, Avengers: Infinity War (2018), was filmed entirely on digital IMAX cameras, making them the first Hollywood films shot entirely on IMAX cameras, in an exclusive open-matte aspect ratio of 1.9:1.
12Joe Russo's daughters
Director Joe Russo's daughters Ava Russo and Lia Mariella Russo respectively portray Clint Barton/Hawkeye's daughter Lila and a Hulk superfan wanting autographs and selfies in Avengers: Endgame.
Scott Lang's storage unit number in Avengers: Endgame is 616, which is the same number used for the primary continuity (Earth-616) of the Marvel Comics Universe.
The line “Clint, son of Edith” in Avengers: Endgame is a Marvel Comics reference. In the comics, Clint Barton and his brother Barney were the sons of Harold and Edith Barton. The boys loved their mother but hated their father, who was a physically and verbally abusive alcoholic. Harold eventually killed both himself and Edith in a DUI car accident, after which Clint and Barney were sent to an orphanage.
In September 2018, the Russo Brothers posted a picture on social media of the Avengers: Endgame set, with the caption “Look Hard.” This led many to speculate and believe the title of this film was hidden (which at that time hadn’t yet been revealed) somewhere inside the photo. In fact, the film's subtitle, “Endgame,” can be made out by the shapes and layout of the objects in the image.
In the early Avengers comics, Clint Barton sheds his Hawkeye identity to become the original Goliath. As Goliath, he used Pym Particles to grow in size. In “Endgame”, he is the first Avenger to test the Pym Particles - a nod to his comics history. Bill Foster (featured in Ant-Man and the Wasp (2018)) later became the second Goliath.
The name “Endgame” for the movie Avengers: Endgame was foreshadowed in Avengers: Infinity War by Doctor Strange: “We're in the endgame now.”
When we see Hank Pym in his lab in the past in Avengers: Endgame, we can clearly see a large, rounded, metal helmet with eye holes and antennae. This helmet resembles the Hank Pym Ant-Man's helmet out of the original Ant-Man comics and Avengers comics.
In Avengers: Endgame actors Ken Jeong appears as a security guard of the storage unit which stored Scott’s van. In his scene, he is shown reading “Terminal Beach”, a collection by J.G. Ballard which includes a story titled “Endgame.”
The 573 area code shown for Laura Barton's phone number in Avengers: Endgame suggests that the Barton family farm is located in central/eastern Missouri, as this is the area code for most of the eastern half of the state outside of the St. Louis metro area. This is confirmed when we see a truck at the Barton farm with a Missouri license plate.