The Solo Leveling anime successfully adapts the manhwa and light novel without any noticeable negative impacts, condensing and contextualizing content to fit the animated style of storytelling. The anime introduces minor changes to certain scenes and characters, such as removing a scene where Sung Jinwoo asks for coffee and changing the character who opens the doors to the double dungeon. The anime includes early appearances of significant characters, such as President Go Gunhee, to provide hints of the deeper political tides that will be explored in the future.

The biggest differences between Solo Levelings anime and the manhwa are subtle but have tangible effects on the portrayal of the story in its new medium. Just the first episode alone exhibits at least ten alterations, additions, or cuts that did not occur in the manhwa, including details ranging from minor incongruencies to the creation of completely new content in terms of story structure.