If Marvel had a dollar for every time they brought Ultron back as a villain, then they'd probably have enough to buy out Disney instead. Hyperboles aside, there are only so many times a comic book or scriptwriter can keep bringing back Ultron before the robot's power levels rise too ridiculously. Ultron's a character who has progressed so exponentially throughout the decades ever since his first appearance back in 1968.
Now, there's an Ultron that can fly, an Ultron that's invulnerable, and an Ultron more powerful than Thanos with Infinity Stones/Gems. It can be a tough affair keeping track of all the versions of Ultron, what with all the spikes in his power trend. Regardless, here's how he measures up against himself. These some of are Ultron's finest models, at the time being. Do treat it as some kind of loose ranking as it's nigh-impossible to gauge Ultron's arbitrary powers scaling and feats.
Updated March 31, 2022 by Sid Natividad: Ultron is a Marvel character that definitely deserves more than one film in the MCU. He's often one of the most constant thorns in the Avengers' side in the comic books, and with his recent outing such as Infinity Ultron in Marvel's What If show, the franchise continues to prove Ultron's Potential.
Hence, it's only a fair service to the villain to recall the strongest version of Ultron. Because there are still quite a lot of him/her/them. It can also be quite difficult to tally up the most powerful Ultron, but this expanded list ought to give fans a broad idea of how Ultron rolls.
15 Ultrog
Appearance:
- Comic books
- Peter Porker, The Spectacular Spider-Ham #15
Somewhere, out there, there's a cartoonish version of Ultron since everything is possible in the MCU due to parallel universes. So in one of the Earths, namely Earth-8311 Ultron took on the form of Ultrog. It's a mashup of King Kong and Ultron created by Kangaroo (Kang) the Conqueror.
Sure enough, Ultrog came with the full Ultron package. That includes the Adamantium and all the physical enhancements. The metal alone makes him a cut above the rest of the Ultrons, particularly the earlier ones who haven't upgraded themselves with the Adamantium armor.
14 Yellowjacket/Earth-1610 Ultron
Appearance:
- Comic books
- Ultimates 2 #6
Yellowjacket is also the villain for MCU's version of Ant-Man and that one was vastly underutilized and underrepresented. Because the original Yellowjacket in the comic books is actually Ultron from Earth-1610. Similarly, he's also related to Henry Pym.
This Ultron inherited Pym's power and can shrink down subatomically and also increase its size. This was enough for Yellowjacket to kill Scarlet Witch and make replicas of himself. He even waged a war against Magneto but was eventually defeated and later destroyed by Pym.
13 Ultron-16/Ultron Unlimited
Appearance:
- Comic books
- Avengers (Vol. 3) #1
The MCU version of Ultron was based on this one. It's an Ultron that starts off as the main villain of the Avengers (Vol. 3) reiteration. This Ultron is more effective compared to its MCU brother though. It was able to infuse itself with Adamantium.
More than that, it managed to revive and replicate all the previous versions of Ultron, thus creating an Ultron army. With this army, Ultron-16 invaded a European city named Slorenia (the chief inspiration for Sokovia) where the Avengers had to take some massive risks in order to stop the Ultron army.
12 Ultron-11
Appearance:
- Comic books
- Marvel Super Heroes Secret Wars Vol 1 #1
Ultron-11 was a revival of a dead and destroyed Ultron. The Beyonder brought him back as part of a supervillain alliance against the Avengers. This version of Ultron started rather weak and was incapacitated by Galactus. However, Doctor Doom modified him with a disintegrator and some cool new powers.
With those, Ultron-11 was able to defeat both Iron Man and Spider-Man, even contributing to blowing up the Avenger's base. When Thor came to the rescue, it was Ultron-11 and his newly installed disintegrator that put an end to the mighty Asgardian. After that, Doctor Doom went mad with power (as always) and kept ordering Ultron to kill the villains. He even managed to kill Kang the Conqueror.
11 Crimson Cowl/Ultron-5
Appearance:
- Comic books
- Avengers Vol 1 #55
It's hard to beat the original and Ultron-5, a.k.a. Crimson Cowl Ultron, was an upgraded version of Ultron-1. He's the one who started it all. Betraying Pym, controlling the most advanced machines on Earth, and skyrocketing his power and place in the hierarchy are just some of his feats.
By disguising himself as the Crimson Cowl, Ultron-5 was also able to form one of the largest villain alliances called the Masters of Evil. Together, they waged war against the Avengers and went down in history as one of the largest villain organizations that the superhero collective has faced.
10 MCU Ultron
Appearance:
- Live-action film
- Avengers: Age of Ultron
Surprisingly, MCU's own Ultron, which also marks Ultron's first outing in live-action, can be considered among the weakest of the bunch. This Ultron failed to defeat the Avengers and all he managed to do was cause property damage and kill a lot of innocents in a provincial city. That says a lot about Ultron's notoriety and capability in comic books and other media.
With that said, this variant of Ultron is still a respectable opponent for the rather reserved Avengers of the MCU. He was a world-ending threat which is impressive enough considering he was merely at the infancy stage in this film. What more could he do if he matured and gained more knowledge?
9 Ultimate Ultron/Ultron-6
Appearance:
- Comic books
- Avengers#66–68
In the comic books, this is the point when Ultron started learning the weaknesses of his usual enemies, the Avengers. It's also the first Ultron to successfully defeat the Avengers. He did so by taking over Vision and reforming his exoskeleton with Adamantium or some kind of alloy that's close in strength to Marvel's fictional metal.
This allows Ultron to become nigh-invulnerable. Moreover, he was already highly intelligent at this point and could also shape-shift by re-arranging his molecules. Compared to the MCU Ultron, this one's much more menacing and caused more damage despite being an older iteration.
8 Hank Pym Ultron
Appearance:
- Comic books
- Rage Of Ultron storyline
Hank Pym created Ultron in the comic books instead of Iron Man. Pym had dubious morals and a plethora of psychological issues. This was reflected well in his robotic creation. Ultron even had some kind of father issues where he yearned for Pym's approval.
Ultron then took it to the extreme and literally fused with Hank Pym (just as he did with Vision). Thus, he gained Pym's intellect which is one of the sharpest in the comic books. The result was catastrophic as this Ultron was able to masquerade as Pym and also use his Ant-Man powers— something he used to deceive and nearly destroy the Avengers.
7 Earth-10943 Ultron
Appearance:
- Comic books
- Avengers (Vol. 4) #5 (2010)
Of course, Marvel simply can't just let Ultron fully win in the main or canon storyline as this would cause a problem for the franchise. Hence, they introduced their parallel universe or comic book "what-if" stories, and the one that featured a more successful Ultron was in Earth-10943.
Now, this Ultron was able to not just defeat all the Avengers of his world but also permanently kill them. He did so by borrowing some of Kang the Conqueror's powers and messing with time and time travel in order to get a huge advantage against the Avengers.
6 Ultron-19/Extremis Ultron
Appearance:
- Comic books
- Mighty Avengers storyline
The Avengers that the prior Ultrons usually fought and defeated typically consisted of the vanilla gang. Thor, Iron Man, Captain America, etc. The later versions of the Avengers have a more stellar lineup, particularly in Might Avengers (Captain Marvel, Wonderman, Sentry, Ares, etc.). Most of them were heavy-hitters and each of them could take on the Hulk single-handedly.
That didn't matter for this version of Ultron which birthed itself from Iron Man's Extremis armors. It could shapeshift, hack the whole world, and toy with all the aforementioned Thor and Hulk-level Avengers. They only managed to stop it thanks to a deus ex machina loophole
5 Ultron the Ruler of the Phalanx
Appearance:
- Comic books
- Annihilation: Conquest storyline
When the Mighty Avengers defeated Ultron— to no one's surprise, he didn't actually die. Apparently, his consciousness lingered around and was drawn to another power source far from Earth, specifically the Babel Spire. It's a world inhabited by the Phalanx, a race of techno-organic aliens. Ultron, consciousness and all, managed to assimilate all of them, thus granting him an incredible army.
With this Phalanx army, Ultron invaded the Kree dominion and even succeeded in conquering a majority of their territory. With his newfound powers and army, he heightened his ambition and even forcibly fused with Adam Warlock, one of the most powerful beings in Marvel.
4 Final Form Ultron
Appearance:
- Comic book
- Age of Ultron (2013)
Age of Ultron, not to be confused with the MCU film, is a comic book storyline that explores a possible dystopian future where Ultron won and took over the world. It's by far his most successful version despite having nearly the same abilities as the canon Earth-616 Ultron.
That's because this Ultron takes a page from Earth-10943 Ultron who can manipulate timelines where he comes out as a victor. Thus, he was able to produce his most powerful but still plausible version here called Final Form Ultron or Gold Ultron.
3 Ultron Forever
Appearance:
- Comic book
- Avengers: Ultron Forever
Avengers: Ultron Forever is a one-shot series that explores a "what-if" scenario for when Ultron became an Asgardian. He was already fusing with several superheroes anyway, so the writers at Marvel had to take a shot at this possibility. Needless to say, this is Ultron at his most omnipotent.
He didn't go for Thor's power, but rather, the Odinforce. This gave him immense potential and also granted him some cosmic and magical capabilities. Harnessing the Odinforce allowed him to stop time and even bring back people from the dead.
2 Galactus Ultron/Earth-22666 Ultron
Appearance:
- Comic book
- Marvel Universe 2001 Millennial Visions
Given his proclivity for fusing with more powerful or smarter sentient beings, Ultron just had to do the ultimate villain union and fuse with Galactus. Well, it wasn't him; it was Silver Surfer who used Ultron's parts to resurrect Galactus. He thought it wouldn't go wrong for some reason.
It did go wrong. This version of Ultron was pretty much Galactus but more malevolent and adaptable. Since Galactus has an infinite power pool, Ultron also managed to tap into this capacity. Thus, he can consume worlds and galaxies and also control all manners of matter and energy. Thankfully, all this was explored in an alternate universe. Otherwise, it would have been too much for the main timeline.
1 Infinity Ultron
Appearance:
- Series
- What If...?
Galactus might have been the hungriest being in the universe but he's still quite instinctive and not too bright. Thanos is still a bigger threat than that creature, especially with the Infinity Stones. So what if someone like Ultron got his hands on Thanos' favorite rocks? That's what Marvel's What If...? TV series explored recently.
Ultron snagged one of the Infinity Stones and used his AI intelligence to utilize it to full capacity. Using that one stone and Vision's body, he lasered a Thanos in half who was wielding five stones. After that, conquering the known universe and defeating the Watcher was a cakewalk for Infinity Ultron.