The Blip was the result of the Time Heist, in which Hulk wore Tony Stark's Nano Gauntlet to reverse Thanos' Snap and its effects on the universe. The event was successful, and the half of the universe that was wiped out by Thanos was revived, although Hulk's attempt at reviving Black Widow simultaneously failed due to the nature of her death.
When all of the Infinity Stones were collected and returned to the present, the Avengers realized that Black Widow had sacrificed herself to gain the Soul Stone. Determined to not let Romanoff's sacrifice be in vain, Tony Stark, Rocket Raccoon, and Hulk began working on a new Gauntlet using Stark's nano technology but based on their knowledge of the Infinity Gauntlet that Thanos had used. Once it was completed, Rocket asked who was going to be the one to actually use it in order to reverse the Snap.
Once Iron Man, Rocket Raccoon, and Bruce Banner had completed assembly of the Nano Gauntlet, Thor volunteered to wear the device, but the other Avengers refused him because he was neither physically able nor emotionally stable enough to wield such power. Bruce Banner warned his teammates that because of the Infinity Stones' unique gamma radiation signature, the Nano Gauntlet could kill anyone who tried to wear it, Thor included.
Banner volunteered himself, explaining that his body would have the best chance to have some resistance to the Stones' radiation and that this made him the most likely to survive using the Gauntlet for their plan. Readying themselves, Stark ordered F.R.I.D.A.Y. to initiate lockdown procedures across the facility in case the Gauntlet's energies proved to be too powerful to contain. Meanwhile, the alternate-2014 Nebula began covertly sabotaging the quantum time travel machine as Banner put on the Gauntlet.
Once worn, Banner channeled the power of the Stones through his body, severely scorching his right arm from his hand up to his shoulder in the process. Focusing to the best of his ability despite the intense pain, Banner screamed as he snapped his fingers, which ultimately resurrected everyone who was a direct victim of Thanos' Snap by safely returning them either to the specific location they disappeared at five years ago or the nearest safe alternative out of danger.
- "I will shred this universe down to its last atom and then, with the stones you've collected for me, create a new one teeming with life that knows not what it has lost, but only what it has been given. A grateful universe."
"Born out of blood."
"They'll never know it. Because you won't be alive to tell them."
- ―Thanos and Captain America[src]
Ant-Man guessed that the mission of resurrecting the universal population worked, as he looked at the inner garden and took notice of a flock of birds that appeared, seemingly out of nowhere, while at the same time Hawkeye received a call from his wife, who had previously perished in the Snap. As the group started to realize their mission had been completed, a dazed Bruce Banner looked up and noticed Thanos' mothership, the Sanctuary II, from above the window ceiling.
Before he could react, the Sanctuary II fired upon the New Avengers Facility, destroying it and causing the Avengers to be separated from each other in the collapsing debris. Hawkeye was able to find and recover the Gauntlet during his fall into the sewers below the facility. Rogers, Stark, and Thor were the only members to have remained on the ground level floor. The trio then confronted the time-remnant Thanos of 2014, who was unimpressed with the results of his initial plan and now sought to use the Stones to reset the universe in his image by shredding it down to atoms and starting over. This confrontation happened concurrent to the time-remnant 2014 Nebula who tricked an exhausted Barton into handing her the Nano Gauntlet.
Following a long struggle, Stark and Thor became temporarily incapacitated, leaving Rogers to face Thanos, who had summoned his armada in full force. The effects of the Blip then became apparent during the ensuing battle when Captain America received a transmission from Falcon, one of the victims of the Snap, and the rest of those resurrected started appearing shortly thereafter through portals created by Doctor Strange and a group of other sorcerers. Ant-Man then became Giant-Man upon finding Banner, Rhodes, and Rocket buried and drowning under the facility ruins, carrying them to the surface for the final battle with Thanos. With the united army of allied Avengers, Rogers led the charge against Thanos' forces.
- "Over five years ago, half of all life in the universe, including our own Midtown High was wiped from existence. But then eight months ago, a band of brave heroes brought us back. They called it the Blip. Those of us who blipped away came back the same age. But our classmates that didn't blip grew five years older."
- ―Betty Brant[src]
All across Earth and the universe, the trillions who were once killed by the Snap were brought miraculously back and at the same age and at the same location that they had disappeared from five years earlier.
In the immediate aftermath, the Blip led to a large amount of chaos and panic. In a Louisiana hospital, for example, Monica Rambeau returned from having been killed in the Snap to find the hospital in chaos as people were randomly reappearing and everyone scrambled to reach their loved ones and help patients, causing the hospital to be overrun. Rambeau discovered that her mother had survived the Snap, but was later killed by cancer. Other doctors, such as Karen Oggerton, were lucky enough to also have their patients be killed and then returned at the same time, so they finished the procedure.
In Midtown School of Science and Technology, the school gymnasium at first seemed to have little-to-no audience with only the players, but then much of the student audience and band players who had crumbled to dust five years ago suddenly been resurrected. Most of the resurrected celebrated their return. The ones who survived the Snap had grown five years older in the time it had taken to bring the victims back to life.
However, the Blip was not without repercussions. As a result of the five years between the Snap and the Blip, many of the previous victims were misplaced from their homes. Meanwhile, resurrected students found themselves five years behind their 2018 classmates due to not having aged the five years. Because many of Midtown High's previously snapped failed to go through the entire school year and take finals, they were told that they had to restart all over again, notably with Peter Parker's class having to retake junior year during the remnants of the 2023-2024 school year.
Behind the Scenes
- The term "Blip" originated in Spider-Man: Far From Home, and was used to describe both half of the population disappearing due to Thanos' Snap as well as their resurrection five years later. However, following the movie's release, Kevin Feige clarified that despite Marvel Studios internally referring to both events as the Blip, the widely accepted adoption of the term "Snap" would now be used to denote Thanos' use of the six Infinity Stones in Avengers: Infinity War, while "Blip" would henceforth be referred to as Bruce Banner's reversal of the Snap in Avengers: Endgame. Despite this, the Snap is referred to as the "Blip" in WandaVision.
- While it is known that the Blip was incapable of reviving individuals sacrificed for the Soul Stone, it is unclear if the Blip revived victims of Thanos's campaign who died through means other than the Snap. For example, Hulk implied to Thor that he could revive the half of the Asgardian population killed during the Attack on the Statesman when convincing him to rejoin the Avengers, but it is unclear if he did so.