CtrlS

CtrlS, or Control+S, is a widely used keyboard shortcut in computer software that triggers the Save command. In most applications with graphical user interfaces, pressing Ctrl+S saves the active document to its existing file, or prompts for a filename if the document has not been saved before.

Platform differences affect its behavior. On Windows and Linux, Ctrl+S is the standard Save shortcut in many programs. On macOS, the equivalent shortcut is Command+S. Some cross-platform applications map Save to both keys depending on the operating system. In web browsers, Ctrl+S commonly opens the Save Page As dialog to store the current webpage.

Other meanings exist in different contexts. In text terminals and many console environments, Ctrl+S is also used as an XOFF flow-control character to pause terminal output, with Ctrl+Q used to resume. This usage is independent of application-level Save shortcuts and may interfere with text input in some environments.

Origin and usage notes. The Save shortcut derives from early word processors and editors that supported keyboard-based commands to speed up editing and file management. The convention spread with graphical user interfaces in the 1990s and remains a fundamental efficiency feature in modern software. While Save is the standard action, some applications implement Save As or auto-save behavior, and some web apps rely on automatic saving, yet Ctrl+S remains a primary means of invoking a manual save in many contexts.