Multiverse

The Multiverse is the collective term for all parallel dimensions in existence.

There are several different universes where the SMG4 and JTSF channels take place.

SMG4 Universe
Unofficially known as the SMGverse and classified as Earth - 8052011 it is where SMG4's universe takes place unlike the JTSF universe it does not contain JTSF. It is where SMG4's SMG4 series takes place and where many Nintendo game locations are along with all the Mario galaxies.

It had a similar history to Nintendo canon until after the events of Super Mario 64, when an alien USB (later revealed to be called a Guardian Pod) crash landed into the Mushroom Kingdom. The Guardian Pod not only spawned the titular character SMG4, but it released a horde of memes and corrupted the IQ of nearly everyone living in the Mushroom Kingdom, including poor Mario. SMG4 would soon discover that he has the power to tame the insane by recording YouTube videos, motivating him to create the SMG4 series. He would drop his Guardian Pod into a gorge to prevent it from causing any further corruptions. Spoiler Warning Throughout the series, an insane Mario and a not as insane SMG4 would go on many crazy adventures with Mario lookalikes, several idiots, crazy memes, and completely original characters. An evil doppelganger of SMG4, SMG3, who also came from a Guardian Pod, would attempt to steal the spotlight from SMG4 for nearly 9 years before he was sent to live in the Internet Graveyard, the place where he was originally supposed to land in. Unbeknownst to anyone, however, a virus had followed SMG4 to the Mushroom Kingdom...

10 years later, almost everyone who had been in SMG4's videos celebrated the channel's 10 year anniversary, including SMG3 and the dead memes. After the party was over, SMG3 prepared to take the dead memes back to the Internet Graveyard, but found that the portal wasn't working. Two creatures from another universe mistaken for hobos (who had arrived at the Mushroom Kingdom a few months earlier) had arrived after the anniversary party to warn SMG4 about the day of reckoning, but it was too late. The dead memes are unable to return to the Internet Graveyard and became corrupted. SMG4, X, FM54321, SMG3, and Mario were abducted by the dead memes and were brought to a cathedral. The creature who lived there was revealed to have been killing off all the Mario Recolors offscreen.

It managed to capture Mario while SMG4 and SMG3 escaped for just long enough to contact their friends for help. The hobos reveal that the creature was a virus from another universe, and it had destroyed theirs. They explained that a Guardian Pod was the only thing that could stop him. Since SMG4 discarded his, they used SMG3's. SMG4 and SMG3 were soon abducted again, prompting the second hobo to tell SMG4 to protect their Avatar without defining what it is. The virus began its attack on Mario, deconstructing SMG4 and SMG3 until SMG4's friends and the two hobos came to save the day. In the climax of the fight, the hobos reveal their names: SMG1 and SMG2, which also reveals that there are more SMGs. They manage to quarantine the virus with SMG3's Guardian Pod, but not without accidentally getting themselves lost in a black hole. The events of the movie caused everyone to develop questions about the existence of the SMGs, Guardian Pods, and Zero, as SMG1 and 2 referred to the virus as. End Spoiler

JTSF Universe
Earth - 8142018 is an Earth very similar to Earth - 8152018 it is where JTSF's series takes place. According to questions asked JTSF confirmed this universe used to be basically a copycat universe of SMG4 until and it is not explained how, why, or when but another Mario recolor named JTSF (which stand for Jerry-The-SMG4-Fan) was born causing a branch in the timeline. According to JTSF this timeline is basically the same as SMG4 except he exists and there are extra arcs.

Normal Mario
A dimension location in the SMG4 series. It is a universe where Mario resides in. When SMG4's Guardian Pod arrived in the Mushroom Kingdom, it did not reduce the IQ of Mario, and when SMG4 told him to do something stupid on the camera, Mario was confused which erased SMG4 from existence as he got cancelled.

BFC
A dimension location in the SMG4 series. It is a universe where Bob Bobowski succeeded Colonel Sanders and became the owner of KFC, which he renamed into Bob's Fried Crap (BFC).

Francis' Victory
A dimension location in the SMG4 series. It is a universe where the SMG4's Gang never stopped Francis and has succeeded in using Inkweaver to create his own Waifu island.

SMG3's Victory
A dimension location in the SMG4 series. It is a universe where SMG3 successfully usurp and upstage SMG4 from his YouTube career.

Waluigi's Victory
A dimension location in the SMG4 series. It is a universe where Waluigi successfully conquer the world and let everyone know how it feels to be rejected.

Bob Bobowski's Victory
A dimension location in the SMG4 series. It is a universe where Bob became a rich famous rapper and betrayed his friends for good.

Office Worker SMG4
A dimension location in the SMG4 series. It is a universe where SMG4 gets a real job.

Supreme Leader Swagmaster6969696969
A dimension location in the SMG4 series. It is a universe where Swagmaster6969696969 and Chris Gordman were the rulers of the Mushroom Kingdom, and the inhabitants of the kingdom rebelled against them for taxing the poor.

Spaghetti Gone
A dimension location in the SMG4 series. It is a universe where the world ran out of spaghetti, and Mario is depressed as he can't eat spaghetti.

Sussy Baka Bob Bobowski
A dimension location in the SMG4 series. It is a universe where Melony referred to Bob Bobowski as a "sussy baka", much to his confusion.

KFC Worker Saiko Bichitaru
A dimension location in the SMG4 series. It is a universe where Saiko Bichitaru works at the KFC supply delivery. She stole a delivery truck and hid it under Tari's bed.

Cease and Desist
A dimension location in the SMG4 series. It is a universe where SMG4 lost the rights of using Nintendo characters for his videos and are being watched by Shigeru Miyamoto.

Melony's Channel
A dimension location in the SMG4 series. It is a universe where Melony ran the SMG4 channel and uses Lil' Chonks toys for videos.

Polite Bob Bobowski
A dimension location in the SMG4 series. It is a universe where Bob tries to be polite.

Voice Swap
A dimension location in the SMG4 series. It is a universe where all character's voice are switched.

Anime SMG4
A dimension location in the SMG4 series. It is a universe where the members of SMG4's Gang said "nani" which angered Toad to the point where he shot at Mario for ignoring the warning.

Mario's Stuck Pingas
A dimension location in the SMG4 series. It is a universe where Mario's pingas is still stuck with the door. He badly needs the toilet.

Simp Melony
A dimension location in the SMG4 series. It is a universe where Melony is watching a video of herself simping over Bob the Tomato and Larry the Cucumber.

Everyone is Bob Bobowski
A dimension location in the SMG4 series. It is a universe where everyone is Bob Bobowski.

SMG4 on Drugs
A dimension location in the SMG4 series. It is a universe where SMG4 was given the above question where he revealed that this was normal SMG4 before getting out of the stage as no one laughed.

Persona 5 Royal Logic
A dimension location in the SMG4 series. It is a universe where the logic of Persona 5 Royal is applied.

Star Wars Logic
A dimension location in the SMG4 series. It is a universe with Star Wars logic where Saiko Bichitaru and Bob Bobowski were fighting over a KFC bucket.

Desti's Survival
A dimension location in the SMG4 series. It is a universe where Desti survives the event of SMG4: World War Mario and get to live her life with her former rival Meggy Spletzer until this universe's version of SMG4 Movie: Meggy's Destiny where Meggy was assassinated by the False Sephiroth who also survived the event and had to fight Desti who wants to avenge her dead friend.

SMG4 Non-Canon
A dimension location in the SMG4 series. It is a universe where all non-canon content from the SMG4 series takes place, such as the opening advertisements.

Custom Mario Logan Universe
A dimension where all the characters from Custom Mario Logan appear like Mario, Jeffy, and the others.

JTSF Non-Canon
The universe where all the things that aren't canon to JTSF's videos like his discord advertisements and intros.

Bootleg Dimension
A dimension location in the SMG4 series. It is a dimension consisting of dank Mario memes, and where 7 Grand Dad come from. It can only be accessed via a corrupted painting made by Professor E. Gadd.

Arcade Dimension
A dimension location in the SMG4 series. It is a dimension that consists of various locations from the NES and SNES games. It could only be accessed with the YouTube Remote.

Meta Runner
The main dimension location of Meta Runner. It is a futuristic and technologically advanced universe where one's ability to play video games are considered a status symbol. On the top of the food chain, there are the titular Meta Runners, people who replaced their limbs with cybernetics in order to improve their gaming abilities. Unlike SMG4, this universe is more realistic, lacking cartoony physics and superhuman abilities in the "real world".

As of now, there is no way to travel to and from this dimension.

Murder Drones
The main dimension location of Murder Drones. It is a post-apocalyptic universe where humans made sentient androids called Worker Drones that served the humans until a Worldwide Nuclear Meltdown happened and took all the humans out, leaving the Worker Drones in a new Ice Age. The Worker Drones try to survive the killer androids known as Disassembly Drones which were made to take out the Worker Drones.

As of now, there is no way to travel to and from this dimension.

Grand Hotel Mario
A dimension location in the SMG4 series. It is a universe where a luxurious hotel is located. This place is visited by many variations of Marios across the universes to get a break and this hotel is run by Don Mario. It can be accessed via a warp pipe.

Mobius
A dimension location in the SMG4 series. It is a universe 12,000 years into the future in the Archie Sonic continuity. It is the home world of Sonic the Hedgehog, Dr. Eggman, Tails the Fox, Knuckles the Echidna, Amy Rose, Shadow the Hedgehog, Rouge the Bat and several others.

Minecraft
A dimension location in the SMG4 series. It is a dimension with 3 pocket dimensions with the Overworld being the largest. It is where Steve and the other Minecraft mobs originate in and can usually be accessed through a portal although sometimes it affects the SMG4 Universe like in Super Mario 64 Bloopers: Castle Creepers and SMG4: The Minecraft Plague.

Internet Graveyard
A dimension location in the SMG4 series. It is a place where irrelevant things of the internet such as dead memes (memes that are irrelevant and outdated with mainstream audiences), irrelevant YouTubers, and obsolete trends that have lost their popularity go to. This place used to be ruled by the five guardians of the dimension before they let SMG3 take over. Before SMG3's takeover, this place used to be only accessible via the YouTube Remote (whether directly via its Oof Buttons summon button or indirectly via making the subject of the videos irrelevant).

Cancelled Dimension
A dimension location in the SMG4 series. It is where people who did "illegal" things on the internet go to and is divided into various sectors: Twitter sector, Clown sector, Hurtful Memes sector, and various other sectors. The only known way to be in said dimension is to be teleported there by the YouTube Remote.

Old Universe
A dimension location in the SMG4 series serving as it's in-universe predecessor. It was a universe that was destroyed by SMG0 and the universe where SMG1 and SMG2 originated from. It's also the universe where the Newgrounds characters originated from. After SMG4 and Mario explored the memories of that universe, the main game of the universe is Spudnick's Great Adventure, with it's main character, Spudnick, being the avatar. It was destroyed by Zero when he killed Spudnick, forcing SMG1 and SMG2 to evacuate everyone living in that universe. Unfortunately, Zero's arm managed to follow them.

SMG0's Universe
A dimension location in the SMG4 series. It was the place of origin where Zero came from. It had Zero and his avatar who is currently unknown. There are currently no appearances of the universe before it got destroyed but for unknown reasons it got destroyed similar to the Old Universe and in the process, a bolt of lightning from an unknown source shocked Zero's possible avatar.

In-Between
A dimension location in Sunset Paradise. It is a dimension where people who die go to. It's not the afterlife and is the dimension where the Pheonix Ashes came from. Anyone that reside in the In-Between can view the actions of their universe of origin. So far, Auri Bori is the only person who entered that dimension by dying and managed to come back.

SMG0's New Universe
In SMG4: War Of The Fat Italians 2021, SMG0 creates a new universe using the memes in the Mushroom Kingdom and uses Mario as his avatar. This universe then collapses after Mario was released from the crystal, his Brainwashed projection, the memes were restored and both SMG0 and Axol both die in the process.

Real Life
It's essentially our world. This is where the Glitch Productions universes are created. Luke and Kevin Lerdwichagul record themselves on advertisements, announcements and Hobo Bros. Characters from the other universes used to occasionally visit this world.

Pocket Dimensions
Over the years, multiple Pocket Dimensions were introduced to the SMG4 series. Usually being created by someone.

The Glitch Dimension
After SMG4 gets a computer from a dumpster, the computer detects a virus, which SMG4 released, instead of destroying it. The virus eventually infects the castle and creates a insane dimension, where logic doesn't exist. The dimension also had an unnamed ghost guide, who quickly left due to Mario's rudeness. The dimension was presumably destroyed when Mario killed the virus.

The Upside-Down
The Upside-Down is a pocket Dimension that seems to resemble Hell although it doesn't seem to be Hell but rather a counterpart of it. It is unknown who made it or how it came to be.

The Rejection Dimension
""Welcome... to the Rejection Dimension!""

- Waluigi War Of The Fat Italians 2018

The Rejection Dimension (or the Friendzone Dimension as called by Mario) is the dimension where SMG4 and Mario were teleported in SMG4: Mario and the Waluigi Apocalypse. Presumably, it was created by Waluigi.

The Backrooms
In SMG4: Mario and The Backrooms, SMG0/Axol created a pocket dimension from the toilets in order to lure SMG4, SMG3 and Mario into the Backrooms. The purpose was to lure them into the cathedral in the Dark Web.

SMG3's Kushroom Mingdom
In SMG4: Welcome To The Kushroom Mingdom, SMG3 with the help of Grand Dad created a Rip-off Kingdom of the Mushroom Kingdom accessible via a portal hidden as a wall in the castle's basement. The Kushroom Mingdom was later destroyed by Bowsur.

Spider-Verse
This dimension in the multiverse is filled with the Spider-People like Spider-Man (Earth-X), Miles Morales, and Spoderman.

Trivia

 * According to Jerry everything canon to the SMG4 universe is canon to his own like the Genesis Arc as shown when SMG1 and Axol appeared in Triple Plumbers - SMG1 The Babysitter
 * Though the multiverse has not yet appeared in Jerry's videos being that everything from the SMG4 universe is canon to Jerry's means that it does exist