The Marvel Cinematic Universe is in the midst of the Multiverse Saga as it builds to the epic two-part event, Avengers: The Kang Dynasty and Avengers: Secret Wars. Along the way, its characters have explored various alternate timelines and realities that have expanded the concept of the Multiverse with each passing title.
Over the course of the Multiverse Saga, the franchise has presented alternate realities of all kinds, including some that are strikingly similar to Earth-616 and others wherein life is frighteningly different. Others still have revisited old properties, making pre-MCU titles canon in the franchise. In order to keep all these realities straight, fans should know exactly what universes have shown up in the MCU so far.
The Sacred Timeline
Earth-616
The Sacred Timeline is the main branch of the MCU, known as Earth-616. It is in this universe that each installment of the MCU takes place, with a few exceptions. The events of this timeline were written and enforced by the will of He Who Remains, a variant of Kang the Conqueror who pruned all branching timelines using the might of the Time Variance Authority.
The Sacred Timeline has just recently been opened up to the Multiverse, with the events of Doctor Strange in the Multiverse of Madness seemingly opening the reality up to the threat of an incursion with another universe. The subsequent fate of this timeline will likely be revealed in Avengers: Secret Wars.
Loki's Branch Timeline
Earth-TRN732 (Pruned)
During the events of Avengers: Endgame, the Avengers accidentally created a branch timeline during their Time Heist in 2012. After the Battle of New York, this world's version of Loki managed to get his hands on the Tesseract, teleporting away and thereby changing the events that should have occurred according to the Sacred Timeline.
This reality's events appear to be exactly the same as those in the Sacred Timeline up until Loki's escape. This Loki variant would later be arrested by the TVA, who subsequently pruned the timeline accidentally created by the Avengers. The Loki variant, however, would manage to avoid being pruned, with his adventures being shown in the Loki Disney+ series.
Thanos's Branch Timeline
Earth-TRN734
During the Avengers' Time Heist in Endgame, a variant of Thanos managed to get his hands on Pym Particles, using them to follow his enemies back to the Sacred Timeline, bringing his ship, his armies, and his children with him. This event culminated in the epic Battle of Earth, which saw Thanos and his followers erased from existence.
However, after the events of the Battle of Earth, a timeline was created wherein Thanos disappears in 2014, avoiding the events of Avengers: Infinity War and the Decimation. Also, the Guardians of the Galaxy were most likely never formed due to Gamora's absence in this branch timeline. Nevertheless, given the TVA's awareness of the Avengers' exploits, it is likely that this universe was pruned offscreen.
Steve's Branch Timeline
Unknown Designation
After defeating Thanos and his armies, Captain America underwent a mission to return the Infinity Stones that the Avengers stole to their respective timelines in an effort to avoid creating branch realities. While it is implied that Steve was able to "clip any branches," he did indeed create a separate reality thereafter when he returned to the 1940s to live his life with Peggy Carter.
While there has been some debate about whether Steve's actions would create a separate reality, the time travel logic introduced in Endgame seems to imply that this was indeed the case. Since Steve later alludes to living a long life with Peggy, it can be assumed that the timeline was not pruned by the TVA, raising questions as to why the organization would allow such a reality to exist.
Sylvie's Timeline
Earth-TRN866 (Pruned)
The events of Loki introduce a female Loki variant known as Sylvie. Residing in what has been termed Earth-TRN866 (with TRN standing for "Temporary Reality Number," indicating a universe not canonically named, but used by the fan base to organize undesignated Earths), Sylvie appears to have lived a more wholesome life than the original Loki, whose parents had lied to him about his adoption from Frost Giants.
Earth-TRN866 was pruned by the TVA when Sylvie was still a child. The variant was arrested by the TVA officers, one of which was Ravonna Renslayer, and taken to stand trial, but she managed to escape their clutches. Sylvie would then dedicate the rest of her life to wreaking havoc for the TVA to clean up.
The Lamentis Nexus Event
Unknown Designation (Pruned)
After being stranded on Lamentis-1 just prior to an apocalyptic event that would wipe out the entire planet and its population, Loki and Sylvie has resigned themselves to their imminent deaths. However, a kindling of love between the two variants sparked the creation of a massive Nexus event, alerting the TVA to the creation of a problematic timeline.
The TVA quickly located this Nexus Event, arresting Loki and Sylvie and immediately pruning the timeline that they had created before it could spiral out of control. It is implied that, had this timeline been allowed to exist, it might have bred an even greater threat to the Multiverse.
The Loki Variants' Timelines
Various Earths, Unknown Designations (Pruned)
In the last few episodes of Loki, the titular antihero finds himself in the Void, where he meets several variants from alternate realities that had been pruned. Among these are Classic Loki, Kid Loki, Proud Loki, Alligator Loki, President Loki, and several others.
Each of these variants appears to be from a universe wherein things took a drastic turn from the Sacred Timeline. Classic Loki, for example, survived the events of Avengers: Infinity War and lived in hiding for an extended period of time. Kid Loki, on the other hand, killed his brother Thor when they were both still children. Each of these timelines appears to have been pruned by the TVA.
A Possible New Timeline
Unknown Designation
During the events of Loki's first season finale, Sylvie kills He Who Remains, unleashing havoc throughout the Multiverse that ends with Loki being stranded in the TVA once more. However, the closing moments of the episode reveal that it is not the same TVA that he had once known, but in fact, one ruled by Kang the Conqueror.
Little is known about this new TVA, but it seems quite plausible that it is located in an entirely separate reality from the one Loki knew. It appears as though Kang and his variants wrote a new timeline after the death of He Who Remains, sparking dozens of questions that will likely be answered when Loki returns for its second season.
The What If Timelines
Various Earths
Marvel's What If...? series explores the depths of the Multiverse, with Uatu the Watcher as the audience's guide to different realities. The first season of the series depicts at least nine different realities during its run, with the upcoming season set to introduce even more alternate Earths.
Among these alternate realities are instances wherein Peggy Carter became a super-soldier, T'Challa was abducted by Ravagers, the Avengers were murdered by Hank Pym, Ultron attained the Infinity Gauntlet and several more. Also among these is a universe where zombies take over the world, a story that is expected to be continued in the upcoming animated spinoff Marvel Zombies.
The Raimiverse
Earth-96283
Spider-Man: No Way Home unleashed the Multiverse like never before after Peter Parker accidentally ruined a dangerous spell concocted by Doctor Strange. The botched spell brought variants from multiple realities to Earth-616, including one of the greatest cinematic depictions of Spider-Man ever, Tobey Maguire, from Earth-96283, known colloquially as the "Raimiverse."
Several variants in No Way Home confirm the existence of Sam Raimi's Spider-Man movies within the Marvel Cinematic Multiverse, including Willam Dafoe's Green Goblin, Alfred Molina's Doctor Octopus, and Thomas Haden Church's Sandman. The ending of No Way Home returns these variants to their homeworld, evidently rewriting their timeline so that each of the multiversal villains survived their respective battles with Spider-Man.
The Amazing Spider-Man Universe
Earth-120703
Alongside certain variants from Earth-96283, Doctor Strange's failed spell in Spider-Man: No Way Home accidentally summoned individuals from another alternate reality known as Earth-120703, the continuity in which Andrew Garfield's Amazing Spider-Man films exist.
No Way Home featured a story wherein Garfield's Spider-Man, Rhys Ifans's Lizard, and Jamie Foxx's Electro were all plucked from their universe and dropped in Earth-616. The film's ending resulted in each of these variants returning home, with little change to their timeline.
The Sony Universe
Earth-TRN688
The Sony Universe is confirmed to exist in the Marvel Cinematic Multiverse after the mid-credit scene of No Way Home, which featured Tom Hardy's Venom. This universe, temporarily designated Earth-TRN688, is the location in which Hardy's Venom films, Morbius, and the upcoming Kraven the Hunter and Madame Web films are all set.
This universe, sometimes called the "Venom-Verse" appears to be closely aligned with Earth-616, as evidenced by Adrian Toomes's accidental travels in the Morbius post-credit scenes. Given the lack of an onscreen Spider-Man in this universe and Marvel's oversight in naming this particular Earth, some fans have theorized that the "Venom-Verse" and Andrew Garfield's Amazing Spider-Man universe are in fact one and the same.
The Magical Multiverse Tour
Various Earths
In an attempt to escape from the Scarlet Witch in Multiverse of Madness, America Chavez and Doctor Strange find themselves tumbling through the Multiverse, jumping in and out of different realities in a matter of seconds. During their fall, they enter no less than nineteen different universes.
In this bizarre and visually stunning sequence, several brand-new universes are introduced, including one entirely made of paint, a cartoon world, several futuristic realities, an Earth comprised of volcanic rock and lava rivers, a reality inhabited by several statued heads of the Living Tribunal, and an Earth that has been taken over by Hydra, as well as several others.
The Utopian Parallel
Unknown Designation
America Chavez, one of Phase 4's best new heroes, is a multiversal traveler hailing from a reality known as the Utopian Parallel. Chavez dwelled in this reality with her family until she accidentally created a portal that separated her from her parents, losing them forever.
Little is seen of the Utopian Parallel so far in the MCU, with the sole exception of a flashback sequence depicting America's tragic origin. However, given its name and brief depiction in Multiverse of Madness, it can be assumed that the Utopian Parallel is a reality of general peace and prosperity.
The Illuminati Universe
Earth-838
During their adventures, America Chavez and Doctor Strange become stranded on a parallel Earth, designated 838, that houses the ill-fated Illuminati. Earth-838 already appears to be adept at multiversal travel, with Dr. Christine Palmer spending much of her time researching different realities and compiling them in an index for future study.
Earth-838 appears to be home to many different groups of superhuman heroes, including the Avengers, the Inhumans, the Sorcerers Supreme, the Fantastic Four, and the X-Men. Their combined might, with the added power of the Darkhold, allowed the Illuminati to defeat Thanos before he could complete the Infinity Gauntlet, saving the universe from his conquest.
Sinister Strange's Timeline
Unknown Designation (Destroyed By Incursion)
After escaping Earth-838, Doctor Strange and Dr. Christine Palmer find themselves in a universe that has been destroyed by an incursion. There is a single inhabitant left in this timeline, a variant of Doctor Strange who unsuccessfully attempted to save his reality using the power of the Darkhold.
This universe shows exactly what happens to a timeline wiped out by an incursion. Reality appears to be fragmenting, disappearing into the white sky in strands of black matter. The Earth seems to be slowly disappearing into nothingness, a reality which shakes Strange to his core, knowing this could be the fate of his own universe.
The Real(ish) World
Unknown Designation
The season finale of She-Hulk: Attorney at Law featured an extended sequence wherein Jennifer Walters bursts through the fourth wall to confront Marvel Studios for his shoddy plotline. She finds herself face-to-face with K.E.V.I.N., a robot tasked with writing each Marvel movie and series.
While it is unclear how She-Hulk's exploits tie into the larger Multiverse story in the MCU, it seems likely that she jumped to a separate reality altogether. This reality seems quite like our own, with the sole exception of K.E.V.I.N's existence. However, the robot's final lines to She-Hulk imply that neither she nor anyone else from the MCU will ever be able to return to this reality again.