alwaysontop

Always on top is a window property that keeps a chosen window above all other non-minimized windows on the screen. In practice, a window marked as always on top remains in the visible stacking order even as the user switches focus among other apps. The exact behavior can vary by platform and window manager, and some systems may still allow full-screen applications to cover topmost windows.

The feature is commonly used for media players, chat overlays, monitoring tools, and utility palettes that should be readily accessible. It may also appear in image or video editing software to keep tools visible while working on a larger canvas. In user interfaces, the option is often exposed as a menu item or a configuration setting labeled “Always on top” or “Stay on top.” In code and configuration, it is sometimes represented by a flag such as AlwaysOnTop or alwaysontop.

Implementation is platform specific. In Windows, the topmost behavior is achieved by setting the WS_EX_TOPMOST style or calling a function like SetWindowPos with HWND_TOPMOST. In macOS, applications can designate a window level above standard windows, such as floating or utility levels. In the X Window System, a window can request the state _NET_WM_STATE_ABOVE to stay above others. Cross-platform toolkits expose equivalent APIs, e.g., setAlwaysOnTop(true) in many UI frameworks, or window flags such as WindowStaysOnTopHint.

Considerations include potential obstruction of other windows, interference with full-screen applications, and accessibility concerns. When multiple topmost windows are present, managing focus and z-order becomes important for a clear user experience.