###### (This is the documentation for SDL3, which is the current stable version. [SDL2](https://wiki.libsdl.org/SDL2/) was the previous version!) # SDL_GetPrimaryDisplay Return the primary display. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_video.h) ## Syntax ```c SDL_DisplayID SDL_GetPrimaryDisplay(void); ``` ## Return Value ([SDL_DisplayID](SDL_DisplayID)) Returns the instance ID of the primary display on success or 0 on failure; call [SDL_GetError](SDL_GetError)() for more information. ## Thread Safety This function should only be called on the main thread. ## Version This function is available since SDL 3.1.3. ## See Also - [SDL_GetDisplays](SDL_GetDisplays) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryVideo](CategoryVideo)