In the scene where Will Smith and Jeff Goldblum are being chased out of the alien mothership, Jeff says "Must go faster, must go faster." In the film Jurassic Park, when Jeff is injured, riding in the back of a jeep, and getting chased by the T-Rex, he says exactly the same line; same emphasis, same tone, same everything.

The humans are out of missiles in the final battle, except for Randy Quaid, who crashes into the alien main weapon, destroying the ship. A number of problems here. First off, a central control center operator reports all the missiles have been fired, indicating they can monitor all planes. But somehow Quaid's missile escaped their notice. Then no one in the control room seems to know where Quaid came from, which they should know if they were monitoring the fighters. Actually these mistakes stem from the original ending, which involved Quaid arriving to the battle in his biplane with a missile strapped to it, because he was too drunk to be given a fighter. He then flew the biplane into the alien ship because he obviously couldn't fire the missile. But producers felt this was too cheesy and filmed Quaid in a fighter, but chose not to film the control center scenes again.

In Area 51 there is a large screen displaying the results of the nuclear strikes against the alien ships. Look under the screen and there is some text in green. Pause the video (VHS, don't know about DVD). It reads: "The purpose of these greenlines is to lead you to believe that these words mean something" on one side, and "And can I see with eye serene the very pulse of the machine Wordsworth" on the other.

In the scene at the start (look carefully) just before Will notices the alien ship, all of his neighbours are packing up and leaving. There is a mailman delivering the mail to one of the neighbours. Always delivering, come rain, shine, or aliens....

When the First Lady is hopping in the helicopter to fly out of L.A., another helicopter is nearby. It flies past a building that has a large IBM logo on it. People are standing on the top of the building, giving the impression that it is one of the first buildings to blow up. Remember that the movie was sponsored by Apple.

The bomber that drops the bomb on the alien ship in ID4 is the direct descendant of the one that does the same thing in War of the Worlds. The earlier craft is the B-49 "Flying Wing," developed for WWII but never produced; it served as the inspiration for the B-2 "Spirit," both designed by Northrop. It was said that Jack Nothrop, the company founder, had eventually left the company bitterly with his dream design shelved. More than twenty-five years later he receives a surprise call from the new company heads for a special presentation. They give him a scale model of their newest and most advanced aircraft - the B-2. With tears in his eyes, he declares, "Now I know why God has kept me alive all these years." Months later Jack Northrop passes away.

A promotional piece that aired in Spain for this film set off a "War of the Worlds" type of wide spread panic. The promo featured a popular Spanish news anchor and the piece ran as if there really WAS an alien attack to occur on July 4. People believed the broadcast and panicked until officials spread the word that this was only a promo for a US movie. Confirmed on DVD commentary.

The role of Captain Jimmy Wilder was played by Harry Connick, Jr. But it was Matthew Perry who was originally cast in that role. He couldn't work around his shooting schedule with Friends. But he didn't back out before he could add his own touch to the movie. He added the "Hold me" line and the head on Will Smith's shoulder to the script during the briefing scene.

The reason for the introduction of the 'biomechanical exosuits' was that actually two alien designs were presented to Emmerich, but since he liked both, the more monstrous design was used for the suits.

ID4 follows the same pattern as War of the Worlds. First when they come to Earth we don't know what they are until they attack. Second there is a battle between an army force and one ship, and the ship wins. Next a bomb is dropped on one and in both movies they survive. And the aliens are killed by a virus in both (albeit of different types).

The little boy who plays Dylan co-starred with Will once before. He played Will's youngest cousin, Nicky, on the television show, The Fresh Prince of Bel-Air.

The movie the kids in the RV are watching (in the beginning) is "The Day the Earth Stood Still", one of many references to alien science fiction in this film.

Other science fiction movies are referenced in this movie, and some scenes pay tribute, in the scene after the nuclear blast, there is a shot where military personal are looking at the results using a night vision camera. If you look, you will notice the remains of the streetlights are bent and resemble the (laser shooting telescopic) eye of the alien ships in the original "War of the Worlds" (1953).

The director asked for input and advice in dealing with some of the subject matter of the film, primarily concerning the use of Jets. However, the United States Air Force refused to cooperate with any aspect of the filming of Independence Day due to the fact that a greater portion of the film revolved around Area 51, a highly classified subject.

At the end of the year of when ID4 was released BBC Radio one (UK) did a radio play based around the film told from the British point of view. Radio One paid respect to Orson Wells by starting the story like it was happening live just as Wells did with War of the Worlds.

There are several references to other science fiction movies in ID4. When Jeff Goldblum turns on his computer, the computer's voice says 'Good Morning Dave' which is a reference to the film 2001.