Slider

Slider lets a person pick a number — or a range, with one thumb per value — where the approximate position matters more than an exact figure: volume, brightness, a price band. The filled range gives instant feedback on how far along the value sits. When the precise number is what matters (a quantity, a price to the cent), a number field is clearer; for a few discrete choices, use a RadioGroup or Select.

Give the slider an accessible name and visible value. A bare track tells a screen-reader user nothing — wire a Label and surface the current value (a readout or tooltip) so the number isn't hidden in the handle position. For a range, label both thumbs ("minimum"/"maximum").

Match step and bounds to the real range. Choose a step that makes every reachable value sensible and set min/max to the true limits; arrow keys nudge by one step, so a too-fine step makes keyboard use tedious. Keep the track wide enough to be draggable on touch.

Don't use a slider for precision or for two states. Exact entry → a number input beside it; on/off → a Switch. Avoid long sliders where a 1px drag changes the value a lot — pair coarse dragging with keyboard fine-tuning.