After Thanos activates the completed Infinity Gauntlet, half of all life across the universe disintegrates, among them Clint Barton/Hawkeye's family. Tony Stark/Iron Man and Nebula are stranded in space following their defeat by Thanos, but are returned to Earth by Carol Danvers/Captain Marvel and are reunited with Steve Rogers/Captain America, Thor, Bruce Banner/Hulk, Natasha Romanoff/Black Widow, James Rhodes/War Machine, and Rocket Raccoon. The team formulates a plan to steal the Infinity Stones back from Thanos and use them to reverse his actions, and the group, including Thor, Captain America, Banner, Black Widow, War Machine, Rocket, Nebula, and Captain Marvel, confronts Thanos at the planet he is residing in, but learn that he had used the Stones a second time to destroy them, preventing their further use. In anger, Thor kills Thanos, but the Avengers are left to cope with their huge losses, with no way to reverse it.
Five years later, as the world still struggles to move on from the catastrophe, Scott Lang/Ant-Man escapes from the Quantum Realm to discover that five years had passed, and that Hope van Dyne, along with half of the population, had disappeared, though his daughter Cassie is still alive, now a teenager. Lang goes to Rogers and Romanoff, and explains that while five years had passed, only five hours had passed for him in the Quantum Realm. The three go to Stark, who is now raising a child with Pepper Potts, and explain their theory that the Quantum Realm can be used to go back in time and steal the Infinity Stones before Thanos is able to collect them. Stark initially rejects their proposal with concern about risking his parenthood, but after looking at a photo of himself and Peter Parker, he decides to test, and succeeds in finding a model that works.
Rogers, Romanoff and Lang recruit Banner, who had since merged his intelligence with the Hulk's strength, to build a machine. Stark joins them after showing Rogers the safer way to time travel, and Rocket, Rhodes and Nebula arrive to join them, too. Banner and Rocket travel to Norway, where the surviving Asgardians, among them Valkyrie, Korg and Miek, are currently living in a place called New Asgard, to recruit Thor, who is now overweight and drinking heavily, despondent over his failure. In Tokyo, Romanoff recruits Clint Barton, who is now a violent vigilante killing various criminals following the death of his family from Thanos' snap. The Avengers all reunite, and after talking about and recalling the Stones' history and their past encounters with either one of the Stones, they formulate the ultimate plan to travel to various points in time, retrieve the Stones, and return to the present to reverse Thanos' actions. During this, Banner notes that changing the past does not affect their present; any changes instead create branched alternate realities.
Stark, Rogers, Banner, and Lang go to 2012 to retrieve the Space, Mind, and Time Stones during the battle of New York. Banner goes to the Sanctum Sanctorum, where he is informed by the Ancient One that taking the Time Stone from her timeline would prevent Stephen Strange's future efforts to stop Kaecilius from destroying the laws of nature. She concedes the Time Stone to Banner, however, after he informs her that Strange had given the stone to Thanos in his timeline, implying Strange had intended for a specific sequence of events to occur for Thanos to be defeated. Banner also promises the Time Stone's return to her timeline in order to prevent any ill effects. Stark and Lang attempt to steal the Space Stone, but their attempt goes awry due to the antics of the past Hulk and the Space Stone ends up in the hands of a captured Loki, who uses the Stone to escape custody. Rogers succeeds in stealing the Mind Stone from undercover Hydra agents, but stumbles across and fights his past self, who mistakes him for a disguised Loki. Lang returns to the present while Stark and Rogers devise and successfully perform another plan to steal the Space Stone from a U.S. Army installation in the 1970s, while stealing further vials of fluid in order to make the journey back home. While there, Rogers catches a glimpse of his past girlfriend, Peggy Carter, and Stark has a heartfelt conversation with his father, Howard Stark.
Rocket and Thor travel to Asgard in 2013 to retrieve the Reality Stone before Malekith uses it against the Nine Realms. While in Asgard, Thor is reminded that his mother, Frigga, would die soon and has a chance encounter with her while Rocket steals the Reality Stone from Jane Foster. Frigga encourages Thor to still be the hero he can always be in spite of his failures, and a re-encouraged Thor returns to Earth with Rocket, but not before Thor retrieves his hammer.
Nebula and Rhodes travel to Xandar in 2014 to steal the Power Stone before Peter Quill/Star-Lord does. As Rhodes returns to the present with the Power Stone, Nebula suddenly malfunctions and remains on Xandar. Her memories are accidentally transferred to her past self, at the exact moment when Thanos was ordering her and Gamora to acquire the Power Stone. Through this connection, Thanos learns that he had ultimately succeeded in acquiring the stones and that his plans have been fulfilled, and learns that the Avengers are trying to undo his future victory. With this new insight, Thanos captures the present Nebula and sends the past Nebula back to the present in her place, locking Nebula in a cell with the past Gamora as her guard.
Romanoff and Barton travel to Vormir in 2014 to retrieve the Soul Stone, though they become conflicted when the Red Skull, keeper of the Soul Stone, informs them that the stone can only be retrieved by sacrificing someone they love. The two fight over who will make the sacrifice, and Romanoff ultimately takes the fall, with Barton taking the Soul Stone back to Earth.
The Avengers all return to the present with the Stones in their hands, but are distraught to learn that Romanoff had sacrificed herself to obtain the Soul Stone. Knowing that there's no way to bring her back, they proceed on with their goal, determined to make her sacrifice worth it. They place the Stones into a Stark-created gauntlet, and Banner, the most resistant to the Stones' gamma radiation, uses it to reverse the disintegrations. At that exact moment, the past Nebula uses the time machine to transport Thanos and his warship to the present, where he attacks the Avengers' compound looking for the Stones and reduces the facility to rubble. The present Nebula convinces Gamora to help stop Thanos by revealing their growing sisterly bond in the future, thus averting her future fate. Nebula and Gamora attempt to convince the past Nebula to betray Thanos as she attempts to take the Infinity Stones from Barton, but ultimately fail to do so and Nebula is forced to kill her past self.
Stark, Rogers, and Thor confront Thanos, who reveals that he knows of his future victory and the Avengers' attempts to stop it, and it has caused Thanos to realize that even if he did achieve his goal of wiping out half of life, the universe would never thrive or be grateful for this act as he had thought, since they're unable to forget the ones they've lost and will attempt to undo this event, just as the Avengers are doing. Because of this, Thanos finally releases his evil side as he announces that he will instead use the Infinity Stones to destroy the entire universe instead of half, and create a new one in his image. Iron Man, Captain America, and Thor engage in a brutal fight with Thanos, with Captain America gaining the worthy power to wield Thor's hammer, but even without the Gauntlet, Thanos is still able to overpower the trio, and soon, his entire army arrives on Earth to destroy it.
Just as Captain America weakly gets up to face Thanos and his army alone, he suddenly gets an unexpected call from his revived friend Sam Wilson/Falcon, and a portal appears, out of which steps the revived T'Challa/Black Panther, Shuri, the already-surviving Okoye, Falcon, and the Wakandan army. More portals soon appear, each created by the revived Doctor Strange, and every hero that died in the snap, including Peter Quill/Star-Lord, Drax the Destroyer, Mantis, Peter Parker/Spider-Man, Bucky Barnes, Groot, Wanda Maximoff/Scarlet Witch, and Hope van Dyne/Wasp, emerges out of the portals, and other surviving allies also join in, including Valkyrie, Korg, Miek and the New Asgard residents, Wong and his sorcerers, Kraglin and the Ravagers, and Pepper Potts in an Iron Man armor of her own. All of the revived heroes and surviving allies join the Avengers as they altogether launch a final assault on Thanos and his army.
In the ensuing lengthy battle, Stark is reunited with Parker, while Quill shares a moment with Gamora, who does not recognize Quill. Ant-Man and the Wasp attempt to activate the other entrance to the Quantum Realm contained in Lang's old van, while several Avengers, including Hawkeye, Black Panther, and Spider-Man, attempt to keep the Stones away from Thanos, who gets into a losing fight against Scarlet Witch, who is avenging Vision. Thanos calls for his warship to rain fire on the Avengers in an attempt to destroy them, but the warship ends up getting destroyed by the timely arrival of Carol Danvers/Captain Marvel. With the help of several female heroes, Captain Marvel attempts to carry the Stones to Lang's time machine, but Thanos destroys it before she can do so. Thanos again fights against several heroes for possession of the Gauntlet, and eventually manages to overpower them, including Captain Marvel, and activates the Gauntlet again. Reminded by Doctor Strange that this is the possible moment where the Avengers win, Stark makes his ultimate choice and rips the Infinity Stones from Thanos' hand before he can destroy the universe, ultimately using them to disintegrate Thanos and his entire army into dust, thus destroying Thanos forever. Potts, Parker, and Rhodes sit next to Stark as he dies from the radiation emitted from the Stones.
Following the battle, the Avengers and all their allies hold a funeral for Stark, whose artificial heart is floated into the sea. Barton, Parker, Lang, and Hope reunite with their families and loved ones, and T'Challa resumes his duties as king of Wakanda. Thor makes Valkyrie the Queen of New Asgard and joins the Guardians of the Galaxy, while Quill is shown attempting to find Gamora, who had supposedly vanished after the battle (although, a deleted scene shows her still there and kneeling before Iron Man's death). Meanwhile, Rogers is tasked to go into the past to return the Stones and Thor's hammer to their original timelines, but decides not to return to the present and to instead live the rest of his life in the past with Peggy Carter. As an older man, he appears before Sam Wilson and gives his shield to him.
- Robert Downey Jr. as Tony Stark/Iron Man
- Chris Evans as Steve Rogers/Captain America
- Mark Ruffalo as Bruce Banner/Hulk
- Chris Hemsworth as Thor
- Scarlett Johansson as Natasha Romanoff/Black Widow
- Jeremy Renner as Clint Barton/Hawkeye/Ronin
- Don Cheadle as James Rhodes/War Machine
- Paul Rudd as Scott Lang/Ant-Man
- Brie Larson as Carol Danvers/Captain Marvel
- Karen Gillan as Nebula
- Danai Gurira as Okoye
- Benedict Wong as Wong
- Jon Favreau as Happy Hogan
- Bradley Cooper as Rocket Raccoon
- Gwyneth Paltrow as Pepper Potts/Rescue
- Josh Brolin as Thanos
Actors whose characters died due to the events of Avengers: Infinity War include:
- Chris Pratt as Peter Quill/Star-Lord
- Zoe Saldana as Gamora
- Dave Bautista as Drax the Destroyer
- Pom Klementieff as Mantis
- Vin Diesel as Groot (voice)
- Benedict Cumberbatch as Stephen Strange/Doctor Strange
- Tom Holland as Peter Parker/Spider-Man
- Tom Hiddleston as Loki
- Elizabeth Olsen as Wanda Maximoff/Scarlet Witch
- Sebastian Stan as Bucky Barnes/White Wolf
- Anthony Mackie as Sam Wilson/Falcon
- Chadwick Boseman as T'Challa/Black Panther
- Letitia Wright as Shuri
- Evangeline Lilly as Hope van Dyne/Wasp
- Michael Douglas as Hank Pym
- Michelle Pfeiffer as Janet van Dyne
- Samuel L. Jackson as Nick Fury
- Cobie Smulders as Maria Hill
- Tom Vaughan-Lawlor as Ebony Maw
- Carrie Coon as Proxima Midnight
- Michael Shaw as Corvus Glaive
- Terry Notary as Cull Obsidian
Reprising their roles from previous MCU films include:
- Tessa Thompson as Brunnhilde/Valkyrie
- John Slattery as Howard Stark
- Tilda Swinton as Ancient One
- Rene Russo as Frigga
- Hayley Atwell as Peggy Carter
- Robert Redford as Alexander Pierce
- Winston Duke as M'Baku
- Taika Waititi as Korg
- Frank Grillo as Brock Rumlow/Crossbones
- Ty Simpkins as Harley Keener
- Natalie Portman as Jane Foster
- William Hurt as Thaddeus Ross
- Angela Bassett as Ramonda
- Jacob Batalon as Ned Leeds
- Marisa Tomei as Aunt May
- Ross Marquand as Johann Schmidt/Red Skull
- Kerry Condon as F.R.I.D.A.Y.
- Hiroyuki Sanada as Akihiko
- Emma Fuhrmann as Cassie Lang
- Alexandra Rabe as Morgan Stark
- Stan Lee as a de-aged 1970s car driver
- Ken Jeong as a storage facility guard
- Yvette Nicole Brown as a S.H.I.E.L.D. agent
- Joe Russo as a grieving man
- Ava Russo as Lila Barton
- Lia Russo as a fan of Hulk
- Jim Starlin as a grieving man
Avengers: Endgame had its world premiere at the Los Angeles Convention Center on April 22, 2019. Disney converted the convention center's Hall K for the film's premiere, working with Dolby and QSC Audio to install a 70 foot (21 metres) screen, Dolby Vision projectors, and a Dolby Atmos sound system. The convention center also held the premiere's red carpet arrival and after party. On its theatrical premiere in the United States, the movie was released in IMAX and 3D on April 26, 2019. It was originally scheduled to be released on May 3, 2019.
- April 24, 2019 (Austria, Australia, Belgium, China, Colombia, Cyprus, Denmark, Egypt, Finland, France, Germany, Greece, Hong Kong, Indonesia, Israel, Italy, Kosovo, Lebanon, Malaysia, Netherlands, Norway New Zealand, Philippines, Paraguay, Saudi Arabia, Sweden, Singapore, Taiwan and Thailand)
- April 25, 2019 (Argentina, Brazil, Cambodia, Costa Rica, Hungary, Ireland, Kwait, Montenegro, Nigeria, Peru, Poland, Portugal, Romania, Serbia, Slovakia, Spain, Turkey, Ukraine, United Kingdom and Uruguay)
- April 26, 2019 (Bangladesh, Bulgaria, Canada, Estonia, India, Japan, Lithuania, Mexico, Nepal, Pakistan, Sri Lanka and Vietnam)
- April 26, 2019 (IMAX version - Morocco)
- April 28, 2019 (Armenia)
- April 29, 2019 (Russia)
On review aggregator Rotten Tomatoes, the film holds a 94% approval rating based on 486 reviews, with an average rating of 8.3/10. The website's critical consensus reads, "Exciting, entertaining, and emotionally impactful, Avengers: Endgame does whatever it takes to deliver a satisfying finale to Marvel's epic Infinity Saga".
- With a running time of approximately 181 minutes (3 hours and 1 minute), it is the longest Marvel Cinematic Universe film up to date and the longest Disney film to date.
- This is the first Marvel Cinematic Universe film not to include a post-credits scene at all.
- It is also the third film in that franchise not to have a post-credits scene after the end credits after The Incredible Hulk and Avengers: Age of Ultron.
- This film features the final Stan Lee cameo, thus ending his "Informant Watcher" character.
- The writers confirmed that trading a loved one for the Soul Stone is a permanent deal. You cannot get back the soul you traded for the stone, even if you return it to Vormir (which forces another sacrifice). This is why Hulk was unable to bring Black Widow back to their timeline, as even the combined might of six infinity stones cannot override the rules for the Soul Stone.
- The stories of the original Avengers come to a close in this film. With Iron Man and Black Widow passing, Captain America retiring and passing on his mantle, and Banner having made his peace with the Hulk.
- The stories of War Machine, Scarlet Witch, Falcon, Spider-Man, Ant-Man, Star-Lord, Rocket Raccoon, Gamora, Drax, Mantis, Groot, Nebula, Winter Soldier, Wasp, Captain Marvel, Black Panther, Doctor Strange, Thor, and Hawkeye are still going.
- The YouTube channel "How it Should had Ended" brought up an interesting plot-hole with the time travel scheme. The Avengers could have simply gone back in time to before Thanos destroyed the Infinity Stones and killed him for them.
- However, it's possible that they didn't want to doom that reality to permanent removal of half the universe as there would have been no way for the Avengers of that universe to know where the stones were unless the present-day versions left the stones for them to use in their reality.
- This film focuses on the multiverse, a concept first introduced in the Marvel Cinematic Universe by Agents of S.H.I.E.L.D., in the season five episode, "Option Two".
- As a result of the events of this film, there exists three more separate timelines/realities of the Marvel Cinematic Universe.
- The first one in 2012, after The Avengers. Loki escaped with the Tesseract, rather than it going to Asgard along with him and Thor.
- The second one is in 2014, at the start of Guardians of the Galaxy. Thanos and his forces traveled to the original timeline/universe in 2023 and were erased from existence.
- The third one is the 1940s, after Captain America: The First Avenger Cap decided to go back in time and live out his life with his love Peggy Carter before returning to the original timeline moments after he originally left.
- As a result of the events of this film, there exists three more separate timelines/realities of the Marvel Cinematic Universe.
- Avengers: Endgame features Edwin Jarvis, who is the only character, originating from Marvel Television, to appear in a film.