The trailer went down a storm with fans, so much so that it's gone a broken a record...a record previously held by Avengers Infinity War.
According to the Walt Disney Company, which owns Marvel Studios, the new trailer racked up a whopping 289 million views within its first 24 hours. Smashing the previous record by 50 million.
Marvel Studios tweeted today to say: "To the greatest fans in the world, thank you for being there from the beginning until the endgame and making this the most viewed trailer in history with 289M views in 24 hours."
The new trailer shows Paul Rudd's Ant-Man will be back for the final instalment of the Avengers as well as Hawkeye (played by Jeremy Renner).
To the greatest fans in the world, thank you for being there from the beginning until the endgame and making this the most viewed trailer in history with 289M views in 24 hours! pic.twitter.com/oWBDCe4e0m- Marvel Studios (@MarvelStudios) December 8, 2018
However, things don't look good for Iron Man/Tony Stark who is shown floating through space with oxygen running dangerously low.
As yet, plot details are scarce, but director Joe Russo has teased fans that the film could be a whopping 180 minutes long.
In an interview with Collider, he said: "I'll say it could easily be a three-hour film."
Before adding: "But I think that, you know, we're very hard on the material. We like it to play at a certain pace. Uh... I... you know, I'm sure that we'll squeeze it.
"I can't imagine... We have a whole year of work left on that movie. I do think it will be longer than Avengers 3 [Infinity War], but it's clearly impossible to say."
The new flick could prove emotional for fans, as a number of the Marvel actors are out of contract after this movie with some having already confirmed that they're hanging up their capes for good.
Chris Evan's (better known as Captain America) has revealed that he won't be back.
In a tweet he wrote: "Officially wrapped on Avengers 4. It was an emotional day to say the least. Playing this role over the last 8 years has been an honor.
"To everyone in front of the camera, behind the camera, and in the audience, thank you for the memories! Eternally grateful."
So, this movie really will be the end of an era for fans.