Methods, systems, and computer program products are provided that enable a user interface of a web development tool to be customized for a web application. A plurality of objects that define a web application is received. The objects are determined to include a customization file that includes a definition for at least one user interface element as a customization to a graphical user interface. The customization file is parsed to receive the user interface element definition(s). A graphical user interface is generated for display that is configured to be interacted with by a user to enable the web application to be developed. The graphical user interface includes one or more user interface element based on the user interface element definition(s) as customizations to the graphical user interface.