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The Best Episodes of Code Lyoko

Every episode of Code Lyoko ranked from best to worst. Let's dive into the Best Episodes of Code Lyoko!

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Four children travel to the virtual world of Lyoko to battle against a sentient artificial intelligence named XANA, with a virtual human called Aelita.

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Seasons4

Episode Rankings

  1. #1 Fan Favorite
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    Code Lyoko Season 3 Episode 8 - Temporary Insanity
    10.0/10(1 votes)

    #1 - Temporary Insanity

    S3:E8

    Before leaving Sector 5, Odd and Ulrich are hit by a weird red beam from a pair of Mantas. They both eventually begin to act strange in the real world during a school play. They start seeing their environment, people as enemies, and fight as if they were still on Lyoko. They are branded as insane and hospitalized while Jeremie tries to figure out what happened. After finding the cause and devising a cure, Jeremie has Yumi and Aelita break them out of the hospital. Meanwhile, Xana uses their handicap to mount an attack on Lyoko's core. Yumi heads to protect the core, as Aelita tries to help the boys who instead now see the real world while on Lyoko.

    Director:Unknown
    Writer:Unknown

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  2. Code Lyoko Season 3 Episode 10 - Nobody in Particular
    10.0/10(1 votes)

    #2 - Nobody in Particular

    S3:E10

    During a test to materialize Ulrich directly into Sector 5, his mind and body become separated, leaving Ulrich's body trapped on Lyoko and his spirit stuck on Earth. What's worse, Xana possesses Ulrich's body and uses it to attack the core. Meanwhile, Susan, disappointed with Ulrich's bad grades, tries to place him in remedial classes.

    Director:Unknown
    Writer:Unknown

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  3. Code Lyoko Season 4 Episode 29 - Fight to the Finish
    9.3/10(93 votes)

    #3 - Fight to the Finish

    S4:E29

    With the Skid gone and XANA's Replikas at unmanageable numbers, Jeremie continues work on his multi-agent system. Meanwhile, Aelita has nightmares about her father being killed by XANA. As Jeremie works, he is contacted by Franz Hopper, who arranges a meeting on Lyoko. William wants to help, but all except Aelita are a little wary of trusting him again. William is left in the lab with Jeremie. After meeting up, Franz transmits the data necessary to finish Jeremie's multi-agent system. However, XANA is not willing to give up without a fight, activating a tower to possess William once again while sending the Kolossus to deal with Franz. Yumi willingly devirtualizes herself and fights William while the others protect Franz. Once Franz is finished transmitting the data, Aelita and Odd head to Sector Five to finish the program. Ulrich, meanwhile, manages to defeat the Kolossus, but its corpse falls on Ulrich, devirtualizing him instantly. However, a problem arises: the energy requirements are too great. Aelita's nightmare is realized when Franz makes the ultimate sacrifice himself to power the program, and in doing so XANA is wiped out completely. Though a great victory for them, the loss of Franz Hopper leaves them with little reason to celebrate.

    Director:Unknown
    Writer:Unknown

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  4. Code Lyoko Season 2 Episode 25 - Revelation
    9.2/10(46 votes)

    #4 - Revelation

    S2:E25

    It's nearing the end of the year and Jeremie's research has hit a dead end. After the group collects some data from The Carthage Region, he plans to use a tower to decipher Franz Hopper's diary. Before the mission, Odd gets a message from a mystery girl. When he goes to meet her, he is attacked by one of Xana's ghosts and locked inside a well at the Hermitage. The ghost then assumes Odd's form and goes to Lyoko in his place. The tower that Xana activated to make the ghost then deactivates, confusing Jeremie. Putting it out of his mind, he begins his plan to decipher the diary. Shortly after they begin, the ghost turns on the group, devirtualizing Yumi and chasing Ulrich away from the tower as three Tarantulas arrive to protect it. At the same time, Xana attempts to take over Jeremie's tower, locking the decoding procedure so they can't abandon it. Jeremie realizes the true nature of the ghost during the fight, and Yumi goes off to find the real Odd. After the ghost proves to be ineffective against Ulrich, it shape-shifts into a clone of Ulrich. In this form, it proves to be an equal match for him. After much fighting, Ulrich finally beats the clone, but is taken out by a Tarantula shortly after. Just when it looks like Jeremie's tower will fall, Franz Hopper steps in and protects it. The diary then decodes fully. After examining the diary, Jeremie tells Aelita that she is Franz Hopper's daughter.

    Director:Unknown
    Writer:Unknown

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  5. Code Lyoko Season 2 Episode 26 - The Key
    9.2/10(50 votes)

    #5 - The Key

    S2:E26

    After going through all of Franz Hopper's diary, Jeremie discovers the truth behind the supercomputer, at least to some extent. Hopper had used it quite extensively, to the point of repeating a single day for more than seven years. His sanity degraded throughout the experience. Hopper also revealed that he and Aelita hold the keys to Lyoko, which Xana was after. He only needed her half, now. The keys would allow him to escape the supercomputer. Jeremie also finds a way to free Aelita from the supercomputer. It turns out that Aelita never had a virus. In fact, Xana had been holding onto a piece of her, which was responsible for linking her to the supercomputer. Aelita is not willing to go, angry over the fact that Hopper had essentially taken her life from her. She's also worried that Xana might escape. To that end, she shuts down the supercomputer. Jeremie rescues her, and the group goes to Lyoko to retrieve her fragment. After all their efforts, they seem to succeed, but it turns out to be a fake. Xana manages to devirtualize Aelita's defenders and steal her memory, effectively killing her and allowing him to escape, which shuts down Lyoko in the process. His escape allows Franz Hopper to revive Aelita and Lyoko, restoring all of Aelita's memories in the process. Through the restoration, Aelita finally remembers her past up to the point that she went to Lyoko. With Xana now free and Aelita's memories returned, neither are linked to the supercomputer. This means that they could shut it down, but it would do no good. Unsure of how they'll proceed, Jeremie promises that they'll find a way to stop Xana.

    Director:Unknown
    Writer:Unknown

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  6. Code Lyoko Season 1 Episode 25 - Code: Earth
    9.1/10(68 votes)

    #6 - Code: Earth

    S1:E25

    As Jeremy is perfecting his materialization program for Aelita, Yumi, Ulrich and Odd are making preparations for her arrival. But as success comes within their grasps, Jim's paranoia aggrivates the already bad situation started by XANA. Due to his injured ankle Jeremy has no choice but to reveal the existance of Lyoko to Jim so he can get to the warehouse. In the end XANA's attack is stopped and Aelita has finally been materialized into the real world. Or has she?

    Director:Unknown
    Writer:Unknown

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    The 20 WORST Episodes of Code Lyoko

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  8. Code Lyoko Season 1 Episode 26 - False Start
    9.1/10(50 votes)

    #7 - False Start

    S1:E26

    Aelita is materialized, but unfortunately, Xana implanted a virus inside of Aelita, so if Xana dies, so does Aelita. Then Xana decides to attack with bringing his own monsters to Earth. Ulrich and Yumi fight off the monsters, while Odd goes to Lyoko with Aelita. Odd eventually get materialized himself, but luckily, Ulrich and Yumi reach the factory, and fight off the last Hornet, attacking Aelita. She deactivates the Tower, and on the second run, the gang is talking with Aelita, about finding an anti-virus, but Aelita can still be materialized for small visits. So they look ahead to the future, and the episode ends.

    Director:Unknown
    Writer:Unknown

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  9. Code Lyoko Season 4 Episode 30 - Echoes
    9.1/10(59 votes)

    #8 - Echoes

    S4:E30

    With their mission completed, the group looks back on all their fond memories of Lyoko. Sissi, meanwhile, plants a tracking device on Ulrich in order to discover their secret. When it comes time to shut down the supercomputer, all but Yumi are unwilling to go through with it: Aelita is still holding onto the hope that her father can somehow be saved, Jeremie doesn't want to take away the thing which made them friends, and Odd and Ulrich both liked being heroes. While they muse over their attachments to Lyoko, Sissi finds her way into the computer lab, and Jeremie's open diary reveals the whole of their adventures. When Sissi tries to explain this to her father, he believes she has lost it and sends her to the infirmary. A return to the past deals with that problem. Ulrich stops Sissi from planting the tracker on the repeat attempt, and the quintet invites her as a friend. Once more at the supercomputer, the group unanimously decides to shut it down, closing the book on their adventures, for now.

    Director:Unknown
    Writer:Unknown

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  10. Code Lyoko Season 1 Episode 22 - Routine
    9.0/10(49 votes)

    #9 - Routine

    S1:E22

    Ulrich is getting tired of getting being rebooted so many times and waiting to find out if Yumi has feelings for him or not. He thinks these are his only troubles, but he is not counting on two things: 1) Sissy getting in the way again and 2) Xana's latest attack which is quite deadly. He disconnects the scanners that makes the return to the real world if he or any of the gang lose all their life points. Instead of returning devirtualized, they could die in Lyoko. Can Aelita shut down the tower in time?

    Director:Unknown
    Writer:Unknown

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  11. Code Lyoko Season 2 Episode 1 - New Order
    9.0/10(64 votes)

    #10 - New Order

    S2:E1

    After discovering Aelita's link to the supercomputer and the inability to shut off the supercomputer that stems from it, Jeremie works hard to find new and better ways to fight Xana. To that end, he develops new vehicles for the group. He also develops a new tower-scanning program that instantly detects activated towers, allowing Aelita to live on Earth. While adjusting to her new life, the class takes a trip to the nearby woods for a scientific field trip. Ulrich wants to partner up with Yumi, but she's already partnered up with someone named William.

    Director:Unknown
    Writer:Unknown

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  12. Code Lyoko Season 2 Episode 3 - Exploration
    9.0/10(48 votes)

    #11 - Exploration

    S2:E3

    After discovering The Carthage Region, the group decides to explore it. Yumi is forced to opt out after her continued late-night trips to Lyoko draw the attention of her parents. While on The Carthage Region, Ulrich and Odd get dematerialized but don't appear in the real world, so Yumi sneaks out of the house to go to Lyoko and rescue Aelita from the Scyphozoa while Jeremie searches for a way to recover Odd and Ulrich. Unfortunately, Yumi's parents discover that she is missing and alert the school, who in turn discover that the other four are missing as well.

    Director:Unknown
    Writer:Unknown

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  13. Code Lyoko Season 2 Episode 10 - Marabounta
    9.0/10(45 votes)

    #12 - Marabounta

    S2:E10

    After deciphering a part of Franz Hopper's diary, Jeremie gets an idea to make a monster that fights on the side of good. By combining techniques, he makes the Marabounta, a sphere that can replicate itself endlessly and devour any monster it can encase. Though it works quite well to begin with, everything goes wrong when it senses Aelita's virus, which is linked to Xana. After Odd attacks it to save her, the Marabounta goes haywire and threatens to devour all of Lyoko, so XANA sends his monsters to help destroy the Marabounta in order to protect Aelita and her memories. The monsters leave the Lyoko Warriors without causing any trouble.

    Director:Unknown
    Writer:Unknown

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  14. Code Lyoko Season 3 Episode 1 - Straight To Heart
    9.0/10(1 votes)

    #13 - Straight To Heart

    S3:E1

    After another three-week vacation, the group is still looking for a way to fight X.A.N.A.. X.A.N.A., meanwhile, is trying to destroy Lyoko, preventing them from doing just that. He does so by targeting the core, which contains the code that maintains the virtual world. In a side story, Odd blackmails Jim into asking Principal Delmas to make Odd have the same classes as his friends. Additionally, Yumi decides against having a relationship with Ulrich and decides it would be better if they were just friends. While defending the core, Aelita is suddenly devirtualized by the enemy. However, she still ends up back in the scanners and Jeremy realizes that this is because Aelita is fully human, just like the rest of the group, so she does not need Code: Earth anymore to be materialized on Earth.

    Director:Unknown
    Writer:Unknown

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  15. Code Lyoko Season 3 Episode 2 - Lyoko Minus One
    9.0/10(1 votes)

    #14 - Lyoko Minus One

    S3:E2

    During a field trip with the rest of her 10th grade class, Yumi finds herself facing off against the students, teachers, and bus driver, all of whom Xana has possessed. At the same time, Xana plans to get rid of Lyoko through an alternate means: destroying each sector one at a time. To this end, he uses the Scyphozoa to possess Aelita and enter Code:XANA into the way tower, wiping out The Forest Sector, realized by Jeremie.

    Director:Unknown
    Writer:Unknown

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  16. Code Lyoko Season 3 Episode 3 - Tidal Wave
    9.0/10(1 votes)

    #15 - Tidal Wave

    S3:E3

    Xana attacks the Lyoko warriors by possessing a large amount of food. At the same time, he bugs up The Mountain Sector by rising the digital sea, but Odd and Aelita go to Sector 5 to stop him. Xana also mounts an attack on Lyoko's core at the same time.

    Director:Unknown
    Writer:Unknown

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  17. Code Lyoko Season 3 Episode 4 - False Lead
    9.0/10(1 votes)

    #16 - False Lead

    S3:E4

    When Xana hacks into a weapon's manufacturing computer network and leaves a paper trail pointing to Jeremie, government agents arrive at the school looking for him. Then, the whole gang arrive at the factory. When they end up tracking Jeremie to the factory, Xana possesses them for an attack on the supercomputer itself in The Ice Sector, and in The Mountain Sector.

    Director:Unknown
    Writer:Unknown

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  18. Code Lyoko Season 3 Episode 5 - Aelita
    9.0/10(1 votes)

    #17 - Aelita

    S3:E5

    Aelita gets mad at Jeremie and she and Odd go into Lyoko without telling anybody, which causes problems. On lyoko, Xana creates a diversion to get everybody to deactivate the tower in The Mountain Sector while the monsters (mostly Mantas and Creepers) worked on destroying the core of Lyoko. Jeremie and Aelita find a strand of DNA that belongs to Franz Hopper, indicating he may be still alive.

    Director:Unknown
    Writer:Unknown

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  19. Code Lyoko Season 3 Episode 6 - The Pretender
    9.0/10(1 votes)

    #18 - The Pretender

    S3:E6

    Odd and Ulrich are talking in the shower room when a young boy, Johnny, asks to talk to Ulrich. It turns out that Johnny likes Yumi, and being jealous of that, Ulrich tells him to follow her around to get her attention, which Yumi hates. After following her all day and ending up in the gym, a flock of crows possessed by Xana attacks Yumi. She is beaten unconscious by their electrified beaks and sent to the hospital. Meanwhile, as Jeremie and the others are fighting monsters to deactivate the tower, the Scyphozoa possesses Aelita and has her enter Code:XANA into the way tower, wiping out The Desert Sector for good and leaving Lyoko with two main Sectors - The Mountain Sector and The Ice Sector. Once Jeremie finds out, he activates a return to the past with strong hope for Yumi's life. This episode proves that Ulrich is not as comfortable as being just friends with Yumi as he says he is.

    Director:Unknown
    Writer:Unknown

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  20. Code Lyoko Season 3 Episode 7 - The Secret
    9.0/10(1 votes)

    #19 - The Secret

    S3:E7

    After being rejected by Yumi, William makes it his mission to find out the secret she's hiding. Soon enough, he manages to follow Ulrich and Odd to the factory and learns about Lyoko and Xana. Meanwhile in The Ice Sector, the Scyphozoa possesses Aelita to enter Code:Xana in the way tower, but is devirtualized just in time. The group thinks William's help is going to be quite useful, when a possessed demolition worker sets several bombs in the factory. They take a vote as to whether or not to include William as part of their group, but Yumi votes no and Jeremie initiates a return to the past.

    Director:Unknown
    Writer:Unknown

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  21. Code Lyoko Season 3 Episode 9 - Sabotage
    9.0/10(1 votes)

    #20 - Sabotage

    S3:E9

    When Xana sabotages the supercomputer, weird bugs begin cropping up in Lyoko. With its power rapidly draining, Jeremie needs to repair it before it becomes completely useless. However, he seems to forget about boys' dorm inspection, so Jim forces him to stay behind. Meanwhile, Xana possesses vines to trip up the rest of the group, except Aelita. Since the attack keeps draining power from the supercomputer, Aelita purposefully wipes out The Ice Sector leaving The Mountain Sector left.

    Director:Unknown
    Writer:Unknown

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  22. Code Lyoko Season 3 Episode 11 - Triple Trouble
    9.0/10(1 votes)

    #21 - Triple Trouble

    S3:E11

    When Odd complains that he doesn't have any cool powers on Lyoko like his friends, Jeremie designs him a teleportation power. It works, but ends up leaving duplicates of himself in the location he teleported from in The Mountain Sector. After trying it twice, Jeremie devirtualizes Odd to find out what went wrong, accidentally creating three clones. Meanwhile, in the real world, Xana attacks using a mysterious smoke that turns anyone it hits to stone. One of Odd's copies gets turned to stone, so the other two Odds must retrieve him before they become unstable and disappear.

    Director:Unknown
    Writer:Unknown

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  23. Code Lyoko Season 3 Episode 12 - Double Trouble
    9.0/10(1 votes)

    #22 - Double Trouble

    S3:E12

    With Xana's attacks becoming more and more difficult to handle, the group contemplates adding another member to the team to make things easier. William is still the prime candidate, but Yumi still doesn't trust him. While Jeremie works on a way to get to Sector 5 directly, Xana makes a clone of him and has it take Jeremie's place. Meanwhile, Yumi has missed one too many classes, and will be expelled if she misses another. Odd and Yumi end up bugged by Jeremie's clone, preventing them from rescuing Aelita from the Scyphozoa. The Scyphozoa possesses Aelita, having her enter Code:Xana into the way tower, wiping out The Mountain Sector, cutting off access to Sector 5. However, Jeremie completes his program to send the group to Sector 5 directly.

    Director:Unknown
    Writer:Unknown

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  24. Code Lyoko Season 3 Episode 13 - Final Round
    9.0/10(1 votes)

    #23 - Final Round

    S3:E13

    After William is initiated into the group, a series of events leaves only him and Aelita to defend Lyoko's core. During William's first mission to Lyoko, Xana uses the Scyphozoa to possess him, making him the general of a massive army focused on Lyoko's core. Despite their best efforts, the group can't stop the possessed William from destroying the core, which both renders the supercomputer useless and transforms William into a darker, Xana-themed version of himself. Later, in the Hermitage, while the group broods over their predicament, Jeremie receives a coded message directly from the internet, sent by none other than Franz Hopper who somehow survived the destruction of Lyoko.

    Director:Unknown
    Writer:Unknown

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  25. Code Lyoko Season 4 Episode 1 - William Returns
    9.0/10(44 votes)

    #24 - William Returns

    S4:E1

    Using the data that Franz Hopper gave them, Jeremie and Aelita succeed in recreating Lyoko, which now holds only Sector Five. Soon after, William is devirtualized, and seems perfectly normal. Sissi decides to make herself "editor-in-chief" of Kadic News, much to Milly and Tamiya's dismay. She soon barges into Aelita's room to interview her and is stopped by William. As soon as William makes Sissi, timay and milly leave,William kidnaps Aelita and takes her to Lyoko. William leads Aelita out of Sector Five and to what used to be The Desert Sector. His intent is revealed to throw Aelita into the Digital Sea. Odd manages to stop him, but William dives into the digital sea. Jeremie concludes that this is Xana's new strategy, and that they must be careful.

    Director:Unknown
    Writer:Unknown

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  26. Code Lyoko Season 4 Episode 27 - Cold Sweat
    9.0/10(41 votes)

    #25 - Cold Sweat

    S4:E27

    When an embarrassing picture of Yumi is printed in the Kadic newspaper, she turns to Odd as the source. He manages to get Ulrich to take the blame, however, causing tension between him and Yumi. Putting that aside, Jeremie sets up a mission to the next Replika, a copy of the Ice Sector. Its supercomputer is located in Siberia, where XANA is growing brains for an unknown purpose. Odd and Yumi are sent to the real world to destroy it, only to be confronted by William. When trying to shut down the tower, Aelita realizes that the data it is generating could be used to free William. After downloading the necessary data and disabling William, everything seems to be set for destroying the Replika. However, XANA draws on the power of his many Replikas to create a new monster: the "Kolossus," a massive creature resembling a fire elemental with a sword for a hand. It easily devirtualizes Aelita and Ulrich, and nearly destroys the Skid, as well. With this new development, and the realization that XANA has hundreds of supercomputers at his command, Jeremie has to change strategies. Meanwhile, Yumi forgives Ulrich for the picture, and Odd admits to his deception soon after. Yumi gets back at both of them by getting a picture of the two coming out of the shower in the paper.

    Director:Unknown
    Writer:Unknown

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Best Episodes Summary

"Temporary Insanity" is the best rated episode of "Code Lyoko". It scored 10/10 based on 1 votes. Directed by Unknown and written by Unknown, it aired on 11/1/2006. This episode scored 0.0 points higher than the second highest rated, "Nobody in Particular".