Unframed mode extends the Isolated Web App (IWA) client area to encompass the entire window, including the regions normally reserved for the title bar and system window controls. This provides developers with complete control over the application's visual layout, enabling bespoke, immersive experiences and custom window branding. In this mode, the application is responsible for rendering all visual elements and handling user input across the entire window surface.
Standard window decorations, including the title bar and system control buttons, impose fixed UI constraints that restrict available screen real estate and visual integration. Without unframed mode, developers are forced to design around standard operating system frames that often conflict with an application’s specific branding or functional layout requirements. While the Window Controls Overlay API provides a lot of flexibility, it still enforces system-drawn regions for window controls, which prevents a fully bespoke interface. Unframed mode enables Isolated Web Apps to occupy the entire window surface, bridging the gap between web and native application experiences. This level of control is essential for immersive software - such as virtual desktop clients - that requires a unique visual hierarchy or a maximized workspace. By removing standard window borders and title bars, developers can implement unique user experiences with branding that matches the feel of native applications.
Docs: https://github.com/WICG/manifest-incubations/blob/gh-pages/unframed-explainer.md
Samples: https://github.com/edman/unframed-demo
Explainers: https://github.com/WICG/manifest-incubations/tree/gh-pages/unframed-explainer.md