HEX to RGBA Converter with Alpha — Online

Opacity fades the whole element, including its text, icons and border, while the alpha inside rgba affects only the property that carries the color. That is why a readable translucent plate is built with an rgba background: with opacity the letters would fade along with the panel.

Something between 0.4 and 0.6 works in practice: the page below stays recognisable without competing for attention. Around 0.8 the layer reads as a solid fill, and below 0.3 the dialog stops feeling separate. Test on both a light and a dark page.

Modern browsers do accept rgba(0 0 0 / 50%), but the field here expects a fraction from 0 to 1. Divide by a hundred: 50% becomes 0.5 and 15% becomes 0.15. Use a dot for the decimal separator, since a comma separates arguments in CSS.

Browser support is universal, but mail clients vary: Outlook on the Word engine frequently drops translucent backgrounds. For newsletters declare a solid fallback color on the line before the rgba value so the layout never renders with no background at all.

The final pixel is a blend of your color with whatever sits underneath, weighted by alpha. Over a dark image, white at 0.3 inevitably reads as grey. If you need the pure tint, raise the alpha toward 1 or place a dedicated layer under the text.

No. Both values stay in the open tab, since the page only splices the channels and the alpha into a string. That is convenient while a palette is still unannounced. On a phone, switch to the numeric keyboard so the decimal separator does not get autocorrected.