Architecture that enables separation of a user interface (UI) upgrade from the content and application logic upgrade. Administrators can upgrade to take advantage of new infrastructure features, and independently schedule the UI upgrade, for example, to accommodate customization work or to ensure user training. Furthermore, administrators can now allow users to choose when to switch to the new UI. More specifically, the architecture facilitates the separation of a UI upgrade from content and application logic upgrade, the ability to control the UI upgrade at multiple levels of precision, the ability for application logic and UI components to change behaviors based on the UI version of the context, and the ability to “preview” the updated UI before permanently switching to it. Additionally, UI components can be filtered to only appear in the appropriate UI version, and the site's UI version can be compared to versions that a component is compatible with.