Changes, cuts and additions in the WIT Studio and MAPPA adaptation compared with the manga.
The 104th Cadet Corps' training period is told briefly in chapters 3 and 4, with a few key scenes (Sasha's potato, Eren's faulty gear, Annie taking Eren down).
Episodes 3 to 5 expand the training with original scenes of the cadets' daily life and additional drills.
The defense of Trost moves quickly, with the cadets' fights resolved in a few panels.
Combat scenes are added, along with more time for Mikasa's thoughts and extra moments of cadets surrounded by Titans.
There is no break: the story continues without recaps.
Between episodes 13 and 14, a recap episode (13.5) aired reviewing events up to Trost.
Hange's introduction and that of Sonny and Bean is brief.
Hange's explanation of her experiments on the captured Titans is extended.
The Female Titan chases down Levi's squad and wipes it out in a few pages.
The chase and the death of the Special Operations Squad are extended with extra maneuvering and tension scenes.
The fight between Eren's Titan and the Female Titan spans a few chapters and ends with Eren ripping Annie out of the nape.
The fight is extended with more destruction of the city, civilian casualties and the Military Police's reaction, before Annie encases herself in crystal.
Each chapter has its own title (for example, “To You, in 2,000 Years” for chapter 1).
Episodes have different titles and, since they combine several chapters, many manga titles go unused, although some are kept.
“Ilse's Notebook” is a special (extra) chapter of the manga.
It is adapted as an OVA, with the story of Ilse Langnar and the talking Titan, and Hange recalls her later.
Levi's past with Isabel and Farlan does not appear in the main manga; it comes from a spin-off.
It is adapted in two OVAs showing how Erwin recruits Levi in the Underground City.
The stories of Annie in Stohess and of Mikasa before Trost are not in the main manga; they come from a light novel.
They are adapted as OVAs: “Wall Sina, Goodbye” (Annie) and “Lost in the Cruel World” (Mikasa).
The story is published continuously.
The films “Crimson Bow and Arrow”, “Wings of Freedom” and “The Roar of Awakening” summarize the seasons with re-edited scenes.
Historia's childhood on the Reiss farm and her mother's death are told in a dedicated flashback chapter (“Krista Lenz”, ch. 52), before Historia is handed over to Rod.
The flashback is moved later: in S3 ep. 3 (“Old Story”) Historia narrates it once she is already with Rod, interwoven with her father's apology (ch. 58).
The Uprising arc is long, with a lot of political intrigue and the subplot of Dimo Reeves and his son Flegel.
Season 3 Part 1 condenses the arc, reduces the political intrigue and cuts back the role of the Reeves Company and Flegel.
Erwin's coup against the false king is told in detail, including Erwin's trial and Zackly and Pixis's maneuver.
The coup is simplified and resolved in less time.
In the cavern, Rod explains the history of the Reiss family and the Founding Titan to Historia before asking her to drink the serum.
The scene is rearranged and condensed, intercutting Rod's explanation with Levi's fight against Kenny's squad.
Kenny's past, his relationship with Uri Reiss and his role with Levi are revealed gradually throughout the arc.
Most of that past is concentrated in the episode of his death, with less detail.
Isayama's art evolves within the same work.
The Final Season moves from WIT Studio to MAPPA and the Titan Shifters are animated in CGI, changing the visual style.
The Marley arc opens with the Battle of Fort Slava, told in a few chapters.
The first episode of the Final Season adds combat scenes and scenes of Marleyan soldiers in the trenches.
The Colossal Titans' advance across the continent is shown in a few pages.
The first final special adds original scenes of cities and civilians crushed by the Rumbling.
In the final conversation, Armin tells Eren: “Thank you for becoming a mass murderer for our sake.”
The line is changed: Armin says he will share his guilt and go to hell with him.
The magazine version of chapter 139 ends with Mikasa at the grave. Volume 34 adds pages: the tree growing, Mikasa visiting it over the years, the future of Paradis and a boy arriving at the tree.
The anime adapts those extra pages as a post-credits epilogue.
The volume 34 epilogue shows the passage of time over Eren's tree in a few panels.
The post-credits scene expands on the passing generations, the war that destroys Paradis and the growth of the tree, up to the boy with his dog.
The last chapters (128-139) are published monthly.
The ending aired as two long specials instead of weekly episodes.
The final arc (ch. 91-139) is published continuously.
It is split into two parts of episodes and two specials, with years between broadcasts.
Kenny slits Dimo Reeves's throat in front of his company, just as Eren and Historia were about to be handed over (ch. 56); his body is taken to Trost and Erwin vows revenge before his family.
Kenny kills him on the way back to Trost while Flegel, who had gotten off the cart, watches from hiding (S3 ep. 2). His cart had already appeared in a cameo added during the evacuation of Trost (S1 ep. 2).
Gabi shoots Sasha on the airship; Sasha dies shortly after saying “meat...”.
The scene follows the manga, but with more time for Connie, Jean and Eren's reactions.