Alt+Tab ↹ is the common name for a keyboard shortcut that has been in Microsoft Windows since Windows 1.0 (1985). This shortcut switches between application-level windows without using the mouse; hence it was named Task Switcher (Flip in Windows Vista).

Alt+Tab ↹ orders windows by most recently used, thus repeated Alt+Tab ↹ keystrokes will switch between the two most recent tasks. It can also be used alternate between a full-size window and the desktop. The window environment maintains a Z-order list of top-level windows (tasks) with the most recently used tasks at the front and the desktop at the bottom, so the most recently used tasks can be switched to the most quickly.

The Alt+Tab ↹ keyboard combination has also been incorporated in other operating systems and desktop environments such as KDE, Xfce, and GNOME. iOS and macOS have similar functionality by pressing ⌘ Command+Tab ↹ but that switches applications rather than windows.

The use of the modifier key Alt in using Alt+Tab ↹ differs from typical modifier key use in the following ways:

There are many subtleties to the behavior of Alt+Tab ↹, and they have remained mostly unchanged over the years.

The behavior follows these rules:

The rules have the following consequences:

When the task list is initially activated by pressing Alt+Tab ↹, the list is populated in this order: