This page contains [backlight](../features/backlight.md) behaviors supported by ZMK.
## Backlight Action Defines
Backlight actions defines are provided through the [`dt-bindings/zmk/backlight.h`](https://github.com/zmkfirmware/zmk/blob/main/app/include/dt-bindings/zmk/backlight.h) header,
which is added at the top of the keymap file:
```
#include <dt-bindings/zmk/backlight.h>
```
This will allow you to reference the actions defined in this header such as `BL_TOG`.
Here is a table describing the action for each define: