Button Forge is a free CSS button generator that runs in your browser with no install. Pick a part in the design panel on the left and its values open in the panel beside it. Every change lands on the preview in the center at once.
The HTML, CSS, and JS panels hold the generated code, ready to paste with the copy button. Numbers step with the half circles at each end, and colors come from the hue ring.
Drag a panel by its header and it snaps to the screen edges and to the other panels. Double-click a panel title to switch between the movable and fixed layouts. The logo at the top left opens the list of the other tools.