Sword Art Online: Hollow Realization (ソードアート・オンライン -ホロウ・リアリゼーション-, Sōdo Āto Onrain -Horō Riarizēshon-) is a video game developed by Aquria and published by Bandai Namco Entertainment for the PlayStation 4, PlayStation Vita, and Windows PC, based on the Japanese light novel series, Sword Art Online. It is the fourth video game in the series and the successor to Sword Art Online: Lost Song. Hollow Realization was released on October 27, 2016, in Japan, and on November 8, 2016, for North American and European territories. A Nintendo Switch version of the game was released on April 25, 2019, in Japan, and worldwide on May 24, 2019.