If you're looking for anime similar to Attack on Titan, you might like these titles. All recommendations are made by Anime-Planet users like you!
In the year 2021, mankind was defeated by Gastrea, a parasitical virus, and was forced to live within a wall made of Baranuim monoliths, a metal that is able to subdue Gastrea. Soon, the "Cursed Children" were discovered: children born infected with the Gastrea virus who possess superhuman abilities. Due to the Gastrea virus' intervention, the Cursed Children could only be female. Civil Securities are formed to specialize fighting against Gastrea, operating with the pair of an Initiator, who are cursed children, and a Promoter, serving to lead the cursed children. Ten years after the war, Rentarou Satomi, a high school student and Civil Security member, and his Initator Enju Aihara, receive a secret mission to prevent Tokyo's destruction.
BB and AoT share few similarities in concept. In both series Humanity is at verge of extinction due a supernatural force at work. Gastrea in BB and Titans in AoT.
Under such circumstances humanity is forced to live inside special walls to keep those entities away from them. Humanity only hope are some trained/special individuals who can fight these abnormal monsters and save themselves from impending doom.
Both have lot of bloodshed,gore and are dark themed, While AoT is mainly composed of adult fighters, BB features special children with gifyed abilities.
If you liked one, You'll likely enjoy other too. AoT is btter of two though