Widget index / Basic controls · Download this HTML
The browser supplies the spin buttons. Type 0 or 21 to try validation.
Ready — try the example.
States and behavior
Editable, increment/decrement, minimum/maximum and invalid typed values.
Keyboard
Up/Down changes one step; typing and native text selection work. Tab exits.
Scope and adaptation
A native number input avoids inventing text editing rules. Its arrow artwork is browser dependent; paired custom spin buttons must preserve the same labeled field and bounds.
Sources
Microsoft preliminary guide (1995), chapters 7–8 · Modern browser accessibility pattern
Original implementation; system colors are represented by CSS variables. The default 13 px system-font stack is a readable browser adaptation. The 1995 source is preliminary, not a final product specification. Test the target browser and native host before shipping.