CSS Box Generator
Use sliders and color pickers to design a CSS box style visually. Control border-radius, box-shadow (offset, blur, spread, opacity, color), border width and color, and background color. The live preview updates instantly and the CSS output is ready to paste directly into your stylesheet.
How to Generate CSS Box Styles
- 1Choose a background color using the color picker
- 2Adjust border-radius with the slider for rounded corners
- 3Set border width and optionally choose a border color
- 4Tune the box-shadow sliders and copy the generated CSS
Key Benefits
- Instant visual feedback as you adjust every property
- Shadow opacity control produces more natural shadows than fixed values
- Copy-ready CSS output — no manual writing required
- Helps you understand how each CSS property affects the visual result
Frequently Asked Questions
What CSS properties does this generator produce?
It generates background, border-radius, border (when width is above zero), and box-shadow. The shadow is expressed as a single-layer box-shadow with horizontal offset, vertical offset, blur radius, spread radius, and an rgba color derived from the shadow color picker and the opacity slider. This covers the most common box styling needs.
How does the shadow opacity slider work?
The shadow color picker outputs an opaque hex color. The opacity slider converts that to an rgba value by applying an alpha channel between 0 and 1. For example, black at 20 percent opacity becomes rgba(0, 0, 0, 0.20). Using a separate opacity slider gives you more precise control than trying to pick a semi-transparent color directly from a color picker.
Can I create a soft card shadow like modern UI libraries use?
Yes. A typical soft card shadow has a small vertical offset (4–8px), a generous blur radius (16–24px), zero spread, and a black shadow at 10–15 percent opacity. Start from those values and adjust until the shadow matches your design. The preview box helps you see the effect in context before copying the CSS.
How is border-radius different from making a full circle?
Setting border-radius to 50% makes a square element perfectly circular. The slider in this tool goes from 0px to 100px — for a perfect circle, the radius needs to be at least half the element's shorter dimension. Since the preview box has fixed dimensions, a value around 64px or higher approaches a fully circular or pill shape. In your actual code, using 50% is the most reliable way to make any square element circular.
Can I add multiple box shadows?
This generator creates a single box-shadow layer, which covers most use cases. For multiple shadows (layered effects, inner glow combined with outer shadow), you would write CSS manually — comma-separate shadow definitions in the box-shadow property. Copy the single shadow from this tool and add additional layers by hand in your editor.
Does this generate inner shadows (inset)?
The current generator produces outer box shadows only. An inset shadow requires the 'inset' keyword in the box-shadow value (for example: inset 0px 2px 4px rgba(0,0,0,0.1)). If you need an inner shadow, copy the generated shadow output and manually add the 'inset' keyword before the offset values.