Systems and methods for defending against emoji domain web address phishing are disclosed. A system may provide computer system security in various instances in which a web address includes an emoji character, which can be rendered as a graphical icon on a user system, and which may cause user confusion leading to a possible computer security breach. The system receives a web address as an input to a web browser. The system processes the received web address to remove any emoji characters present in the received web address. The system compares the processed web address to the received web address and determines whether the processed web address matches the received web address. Various actions are performed to prevent successful phishing attempts against users based on whether the processed web address matches the received web address.