useDeviceKind

Signature

useDeviceKind(override?: DeviceKind): DeviceKind | null

The machine the window's width currently selects, or null before mount.

Notes

Passing override is not the same as ignoring the return value - with an override, no matchMedia listener is attached at all, so a component that switches between "auto" and a forced device by toggling override on and off also switches between listening and not listening, with no leftover listener from the other mode.

There is no third state for "the environment cannot tell": null covers both "not mounted yet" and "no matchMedia available", because both cases call for the same fallback behaviour - use the narrowest machine's numbers, never assume laptop.