This disclosure provides various embodiments for checking user interfaces' compliance with user style guide rules in connection with a UI development tool. A particular digital UI model is identified in a plurality of digital UI models, each UI model representing attributes of a corresponding software application user interface in a plurality of user interfaces available for access by a UI development tool adapted to modify attributes of user interfaces in the plurality of user interfaces. The particular UI model represents attributes of a particular user interface accessed by the UI development tool. The particular UI model is parsed to determine that at least one attribute of the particular user interface violates at least one UI style guide rule. Results are presented in a user interface of the UI development tool, the presentation indicating that the particular attribute of the particular user interface violates the UI style guide rule.