What is alpha compositing?

Alpha compositing is the process of combining a foreground color (with partial transparency) with a background color to produce a fully opaque result. The formula is: out = alpha × fg + (1 – alpha) × bg, applied independently to each R, G, and B channel.

Why does the background color matter?

A semi-transparent color has no single "true" RGB equivalent — it looks different depending on what is behind it. The background color you choose determines the perceived result, which is why this tool asks for it.

What happens when alpha is 1.0?

When alpha is 1.0 (fully opaque), the background has no effect and the output RGB equals the input RGB exactly.

What happens when alpha is 0.0?

When alpha is 0.0 (fully transparent), the foreground has no effect and the output RGB equals the background color exactly.

Can I paste a full rgba() CSS string?

Yes. Use the "Parse rgba()" field to paste a string such as rgba(255, 87, 51, 0.6) and the tool will extract all four values automatically.

Is any data sent to a server?

No. All computation runs entirely in your browser. Nothing is transmitted to any server.

RGBA to RGB Converter

Name: RGBA to RGB Converter
Availability: InStock
Author: Nham Vu

Enter RGBA values and a background color to get the equivalent opaque RGB result via alpha compositing.

Foreground RGBA Input

R — Red

G — Green

B — Blue

A — Alpha

Color Picker Sets R, G, B channels

Parse rgba() String

Background Color

Presets:

Composited RGB Result

Foreground (RGBA)

rgba(99, 102, 241, 0.60)

Result (RGB)

rgb(168, 169, 244)

CSS rgb() Value

HEX Color Code

R (Red)

G (Green)

B (Blue)

Formula: out = α × fg + (1 − α) × bg — applied per channel (R, G, B).

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Summary

Enter RGBA values and a background color to get the equivalent opaque RGB result via alpha compositing.

How it works

Enter R, G, B values (0–255) for your foreground color.
Set the alpha value (0.0–1.0) representing the foreground opacity.
Choose a background color using the color picker or enter its hex code.
The tool applies the alpha compositing formula: out = alpha × fg + (1 – alpha) × bg.
The resulting solid RGB values and hex code are displayed with a live color preview.
Copy the result as rgb(), rgba(), or a HEX code with one click.

Use cases

Flatten a semi-transparent design token to a solid color for export.
Find the perceived color of an RGBA overlay on a white or dark background.
Convert CSS rgba() colors to opaque rgb() equivalents for email clients that ignore transparency.
Determine the solid fallback color for a translucent UI component.
Generate print-safe solid colors from screen colors with alpha channels.
Verify how a translucent layer will look over a specific brand background.

Frequently Asked Questions

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Last updated: 2026-05-28 · Reviewed by Nham Vu