- "I'm sorry; Crisis is over, we beat the bad guy, and you're still worried because...?"
"Because an infinite number of Earths experienced a cosmic heat death from which only one Earth was rebuilt."
"So now, not only do Superman, Supergirl and Black Lightning live here; but now, our entire timeline has been rewritten so that they've always lived here, and I don't remember owning this shirt!"
"Great shirt. Besides; isn't that a good thing; we're all one big happy family now?"
"No. No. No it is not. Not when these guys are crashing the reunion. Not a single one of our doppelgängers survived to make it to Earth-Prime as far as I can tell; but, we did manage to pick up a butt-ton of bad guys, and aliens, and more metas; and you know the best part? The best part is a bunch of our old villains are back with fresh paint jobs!"
- —Frost and Cisco Ramon[src]
Following the Crisis, with the multiverse having been reborn and multiple Earths being merged, there are changes from the original multiverse. According to Gideon, there are about 3.725 trillion changes to reality as a result of the Crisis.
- 1 Known changes
- 2 Individuals with pre-Crisis memories
- 3 Refugees from the original multiverse
- 4 Loom of Fate
- 5 Behind the scenes
- 6 References
- "Eden Corps, the Top, Rainbow Raider... our Earth has more threats than ever, and we don't even know where they're coming from."
- —Cisco Ramon[src]
- Elements of Earth-1, Earth-2, Earth-38 and Earth-TUD5 were recreated in Earth-Prime, to such a convincing extent that the Paragons, who are natives of the former two, consider the worlds to have merged, as do other Earth-Prime residents who were given back or otherwise retained their memories from one of these universes. In this regard, Barry Allen and Kara Danvers were only able to tell the difference when they encountered each other in National City.
- Due to the absences of Earths merged into Earth-Prime, new ones took their place.
- For example, the new Earth-2 is the home universe of the Stargirl TV show.
- The universes are not separated in the same way they were in the old multiverse, as Cisco and Querl Dox are unable to detect the other universes through their vibrational frequency.
- Most inhabitants of Earth-Prime were unaware of any changes to their existence, with the exception of selected individuals (primarily direct allies of the Paragons) being made aware of the changes through a direct mind link with J'onn J'onzz, something considered too dangerous for J'onn to attempt on a wide scale. In addition, an agreement between Lex Luthor and the Monitor resulted in Lena Luthor retaining her pre-Crisis memories.
- J'onn is known to have restored the memories of Team Flash, Team Arrow, the Legends (post Heyworld), Black Lightning, the Superfriends and Superman.
- The Paragons do not have memories of Earth-Prime prior to the Crisis; for example, Supergirl has no memory of willingly filming a TV commercial with Lex and Lena to promote the D.E.O. Additionally, it seems that when individuals have their memories restored by J'onn, it overwrites any memories of their activities on Earth-Prime, as Clark Kent was caught off guard when Lois told him that he had more than one son, Cisco could not remember owning a Superman t-shirt, Jefferson Pierce did not remember that Anissa was alive, and Alex Danvers did not recall that the D.E.O. had Lexosuits but not anti-Kryptonite equipment; things they would have remembered if J'onn did not restore their memories.
- At some point in 2020 after Crisis, Cisco created a device that allows both the Pre-Crisis and Earth-Prime memories to coexist, as seen with Mia Queen. Abra Kadabra found one of these in the Flash Museum, which he later used on himself to regain his missing memories.
- Despite the Paragons have no memories of Earth-Prime before Crisis, Kara could somehow still remember Mitch kidnapping her or tried to during her Midvale High School Prom back in 2009 when he resurfaces in National City Post-Crisis. 
- After the Crisis, any doppelgängers landing on Earth-Prime eventually die of neurological degeneration due to a multiverse anomaly. For example, the doppelgänger of Beth Kane and Earth-Prime Beth Kane suffered headaches because of this, until doppelgänger Beth died. However, if the doppelgänger is dead on Earth-Prime, the one that landed on Earth-Prime will not suffer from this anomaly; for example, Laurel Lance of Earth-2 survived because her Earth-1 doppelgänger was still dead in Earth-Prime's timeline.
- Since universes are not separated by vibrational frequencies, Extrapolators no longer work (but they still exist, non-functional). It's unknown how this has affected the Breacher Agency, if it still exists.
- Earth-Prime retains mementos left behind by previous Team Flash allies from the old multiverse. Frost found Naltorian brandy left behind by a Wells (presumably Sherloque).
- Some individuals were able to retain their pre-Crisis memories through means other than having a link with J'onn. For example, Gorilla Grodd was able to retain his memories from before Crisis due to his psychic powers, and Damien Darhk retained his memories after being restored on Earth-Prime as an Encore.
- Abra Kadabra's family was erased from existence due to Crisis.
- Some people had their species changed by the creation of Earth-Prime; like Morgan Edge.
- The Fountain of Imperium exists on Earth-Prime; it didn't exist on either Earth-1 or Earth-38.
- "Of course, life will go on. It always does. But how? What twists and turns it will take, I can't say. I don't know what the future holds...except to say expect the unexpected. Oliver may be gone, but his mission endures. That mission lives on, Oliver lives on, in the people he inspired. Some will take that mission to the rest of the world...maybe even beyond that. Because if the past eight years has shown us anything...it's that this universe is far bigger than any of us could have dared imagine. Even if it is a little less bright, without him in it."
- —John Diggle's eulogy at Oliver Queen's funeral[src]
- The restored John Diggle and Lyla Michaels now have two children: Sara Diggle originally from the Earth-1 pre-Flashpoint timeline, and John Diggle, Jr. originally from the post-Flashpoint timeline, instead of only having one child or the other.
- Instead of not being able to use her sonic scream after getting her throat slit as using it inflicts pain, Dinah Drake has had her powers restored to their full extent as she was seen using them in the future.
- Instead of witnessing the death of his mother at the hands of Slade Wilson, Oliver manages to save Moira Queen. Additionally, Tommy Merlyn, Emiko Adachi and Quentin Lance are still alive in 2020, and do not meet the same fates as they did on Earth-1 in the original multiverse.
- The Queen Mansion was restored after having been destroyed in the Pre-Crisis timeline.
- The S.T.A.R. Labs particle accelerator would explode in early 2014 instead of the original date of December 11, 2013. However, despite this date change, Barry would still remain in his coma for 9 months and the date he woke up on, October 7, 2014, remains unchanged.
- The layout of Central City is significantly different. For example, the cemetery where Barry's parents are buried in a completely different part of the city compared to the pre-Crisis timeline.
- A number of super-villains of Central City apprehended by Team Flash or killed on Earth-1 are now alive and free on Earth-Prime, for instance Weather Witch, who attacked National City shortly after the Paragons were brought to Earth-Prime.
- Some former allies, like Pied Piper, never reformed, remaining as villains.
- Other returning villains include everyone listed in Cisco's Who's Who? Binder and Hannibal Bates/Everyman.
- The bus metas created by DeVoe are alive again.
- It is possible he created a device to harness their powers instead of stealing their consciousness.
- Zoom, Savitar, DeVoe and Cicada are still dead.
- Devoe used his Hoverchair to get his powers instead of the Thinking Cap. 
- Amunet Black knows who the Flash is, from an unspecified encounter.
- Barry learned to throw lightning a year earlier.
- Seeing as the bridge battle with Pied Piper in "" happened on Earth-Prime, the events of Barry traveling back from 2016 and changing the timeline in "" happened differently or not at all.
- Since the multiverse was never discovered on Earth-Prime, villains from an alternate Earth were altered.
- Zoom is apparently from Earth-Prime instead of Earth-2 and marched into Central City with an army of meta-humans, with all of them having presumably received their powers from the singularity.
- The Earth-X invasion was altered into an invasion of time-traveling Nazi clones.
- Gorilla City exists on Earth-Prime and was the source of a gorilla invasion led by Grodd.
- For an unknown reason, the minds of every Harrison Wells who died in the Crisis who weren't on Earth-1 ended up in Harrison Nash Wells' mind after he was resurrected on Earth-Prime. This included Eobard Thawne, who had Wells DNA due to his disguise, though he has since been exorcised from Nash. Harry and Sherloque tried to warn Nash about Eobard and to get Nash to face his guilt, so Eobard couldn't use its negativity to take over his body.
- This also means that Harrison "Nash" Wells no longer has multiverse doppelgangers.
- Now home to Jay Garrick and Joan Williams; since Henry Allen and Nora Allen are dead, they do not have to worry about neural dissonance. 
- "People think he's a good guy?"
- "Kara, we're talking about Lex Luthor. He's the best guy."
- —Kara Danvers and Alex Danvers[src]
- L-Corp was erased from existence, and Lex Luthor is still the owner of Luthor Corp, as well as now the Department of Extranormal Operations, which is now a subsidiary of Luthor Corp.
- The National City D.E.O. headquarters is the only base on Earth-Prime; the desert facility from Earth-38 doesn't exist.
- Lex Luthor is seen by the public as a good person on Earth-Prime, even receiving a Nobel Peace Prize. Lex had never been revealed as a villain and therefore while the Children of Liberty and Red Daughter still existed due to Lex's influence along with his conflict with Superman, he was never caught by the public for those events.
- In the original multiverse, Andrea Rojas was Russell Rogers' girlfriend and an assassin for Leviathan. In Earth-Prime, she is still working for Leviathan but she was never an assassin. She also never met Russell Rogers.
- Eve Teschmacher's mother, who was dead in the pre-Crisis timeline, is now alive.
- Niles Jarrod is killed by Lex Luthor, instead of Caroline O'Connor.
- Large quantities of Kryptonite were stored in the D.E.O. National City Headquarters, whereas, in the original multiverse, Superman destroyed all samples of the substance.
- Safehouses once owned by Leviathan are no longer present.
- "Clark, I need you to get to Metropolis now, it's the boys."
- "The boys?"
- —Lois Lane and Clark Kent[src]
- Rather than having just one son (Jonathan Kent), Lois Lane and Clark Kent have two children (Jonathan and Jordan Kent).
- reveals that their sons were born in 2007 as opposed to 2019, like their son in the original universe.
- Morgan Edge apparently never crossed paths with Supergirl or Lena Luthor and has a reputation as a ruthless business man. He also isn't in jail. In late 2017 on Earth-38, Edge had arrested after Lena Luthor proved he was trying to kill her in a double trap for her adoptive mother.
- Sam Lane knows that Clark Kent is Superman in this universe and rather than being against him is actually an ally who believes people need Superman and thinks that his life as Clark Kent is a distraction from saving the world.
- Clark and Lois married back in the 2000s; pre-Crisis, he proposed in 2018.
- Pre-Crisis, Clark was wrapped in a blanket when he was sent to the Earth of Earth-38. Post-Crisis, he was not wearing anything when he was sent to the Earth of Earth-Prime.
- Pre-Crisis, Clark was unwilling to work with any form of government assistance due to Project Cadmus. Post-Crisis, Clark works with his father-in-law and the army when necessary. Since Lex owns the D.E.O. on Earth-Prime and never had a feud with Superman, Lillian likely had no reason to found Cadmus though Jeremiah Danvers worked for a company called Cadmus on Earth-Prime.
- "I thought Kenny was killed when you were in high school? The sheriff was running a drug ring and he got caught up."
"No, that's one of those old-world-new world differences. In this world, Kenny never got killed."
- —J'onn and Alex on Kenny's survival on Earth-Prime.[src]
- Kenny Li is alive as of 2009, having a romantic relationship with Kara Danvers; he knows that she has powers and assists her in helping people in the town with difficult situations, but his father passed away sometime prior.
- In the Vanishing Point, Barry needed a boost to get back in to the Speed Force to reach the dawn of time, and when the Spectre gave him that boost, the Spectre's energy accidentally poisoned the Speed Force. As a result, the natural Speed Force died.
- "No. This isn't right. The Phantom Zone's been fractured somehow. Of course. Crisis. When all the timelines converged into one, the opposite must have happened here. It's no longer one pocket dimension, but many; an inter-dimensional archipelago."
- —Querl Dox[src]
- When the timelines of multiple Earths merged as a result of the rebirth of the multiverse, the opposite happened within the Phantom Zone, causing the single pocket dimension it had been to split into many.
Alterations to the timeline
- For further information, see Timeline of Earth-Prime.
- Hong Kong is infected by the Alpha-Omega virus in 2009 instead of 2010. (According to Cisco's timeline)
- The Legends formed in 2015 instead of 2016. (According to Cisco's timeline)
Creation of the new multiverse
- For further information see Multiverse § Post-Crisis.
After the Paragons created Earth-Prime at the dawn of time, it started to multiply itself by possibilities and a new multiverse was rebuilt with some of the pre-Crisis Earths being restored as well. However, residents of Earth-Prime did not discover the new multiverse as the multiverse was separated with an unknown constant instead of vibrational frequency. The list below shows the known Earths in the new multiverse.
Individuals with pre-Crisis memories
- "The only people that know the truth are the ones whose memories have been restored. So it's Brainy, Nia, Kelly..."
- "All the heroes who helped at the Crisis, including you know who, which just makes my blood boil."
- —Alex Danvers and Kara Danvers[src]
After the Paragons restored the multiverse, most residents of Earth-Prime do not naturally remember the events of the original multiverse. Barring special cases - Lex Luthor's deal with Mar Novu for Lena to retain her memories, Charlie's multiverse-awareness abilities as a Fate, and Grodd's psychic abilities - only genuine survivors of the Crisis - i.e. the Paragons, Jennifer Pierce and refugees from other pre-Crisis Earths - have retained their memories. However, J'onn J'onzz was able to restore the memories of the allies of the Paragons. Even residents who had died are aware of Crisis in some way, like Damien Darhk and Astra Logue while being in Hell. Unfortunately, restoring the memories of the residents of Earth-Prime will change a tremendous amount of lives and relationships on Earth, and as such is unfeasible at best. After the funeral of Oliver Queen, Cisco Ramon was able to replicate the psychic powers of J'onn J'onzz and made a ring which can restore individuals' pre-Crisis memories. Eobard Thawne presumably retains his pre-Crisis memories surviving the destruction of the multiverse within his Negative Speed Force, as his body was destroyed, but his spirit and consciousness were preserved and furthermore his memories.
Below are the individuals who were given memories of the original multiverse or kept their memories via various reasons despite not being told by the individuals who were given their pre-Crisis memories.
Refugees from the original multiverse
After Crisis, most people from the original multiverse did not survive so their current versions were recreated by the Paragons and the Spectre at the Dawn of Time. Luckily, a small amount of doppelgängers survived and sought refuge on Earth-Prime. However, the doppelgängers who landed on Earth-Prime will die naturally due to a multiversal anomaly with an exception of those whose doppelgängers are already dead or do not have a doppelgänger on Earth-Prime. The list below shows the refugees that made their way to Earth-Prime.
Loom of Fate
- "My sisters are coming after me. They have been ever since I destroyed our Loom. [...] I scattered the Loom pieces across the multiverse, which took away my sisters' powers. But, now they're all in one universe; thanks to Sara and her merry band of Paragons, the Loom pieces are back on one plane."
- —Charlie/Clotho tells the Legends about how the Crisis put all the pieces of the Loom of Fate in the same universe.[src]
Behind the scenes
- An out-of-universe change is putting an end to the replacing Harrison Wells gag of The Flash since season 2. Every Wells from the Original Multiverse is in Nash Wells' mind; this benefits in-universe as Earth-Prime is cutoff from the New Multiverse.
- The gag has been replaced by Wells having multiversal knowledge from his travelling experiences and/or access to the memories of his doppelgangers.