Alternate versions

The director Kim Jee-woon made seven cuts between 80 to 90 seconds in order to receive an '18' (youth not allowed) certificate by the Korean Media Board (film censorship board). The cuts were made to one scene of body parts being eaten by a dog and humans, and a human body being mutilated. Before the censorship decision, the Korean censors twice gave the film a 'Limited' certificate which means to prevent a video and mainstream theatrical release. After cuts, it was later re-rated '18'.

The German ratings board FSK denied the uncut film its highest rating "Not under 18". Approximately 11 minutes were cut from the film to achieve this rating after all. For the release of the uncut version, the film was approved by an independent legal committee (because the legal committee of SPIO denied an approval).

In the end, the background music played is different in both the Korean and International versions. While in the Korean cut, the BGM that plays is emphasized and said to be forming the film's definite ending. In the International cut, the BGM is less emphasized and instead, the hero's crying voice is heard, ending the film with focus on the character.