# SDL_GetPrimaryDisplay

Return the primary display.

## Header File

Defined in [<SDL3/SDL_video.h>](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 3.2.0.

## See Also

- [SDL_GetDisplays](SDL_GetDisplays)

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[CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryVideo](CategoryVideo)