Which format should I use in CSS?

All three work in modern CSS. HEX is compact, RGB is familiar, and HSL makes it easy to adjust lightness and saturation by hand.

Does it support transparency?

The core converter focuses on solid colors; for transparency you can add an alpha value in rgba() or hsla() in your stylesheet.

Convert colors between HEX, RGB, and HSL and tweak channels with sliders. Copy CSS-ready values for design systems, themes, and marketing pages.

HEX, RGB, and HSL together. Edit any channel; swatch updates live.

HEX

RGB

HSL: hsl(175, 84%, 32%)

Example: #0d9488 is a teal you can express as rgb() or hsl() in stylesheets.

Which format should I use in CSS?: All three work in modern CSS. HEX is compact, RGB is familiar, and HSL makes it easy to adjust lightness and saturation by hand.
Does it support transparency?: The core converter focuses on solid colors; for transparency you can add an alpha value in rgba() or hsla() in your stylesheet.