What Is the Alpha Channel?
The alpha channel is the fourth component in color formats like RGBA and ARGB. While R, G, and B control the color, alpha controls opacity — how transparent or opaque the color/pixel is.
Alpha Values Explained
- Alpha = 0 or 0.0: Completely transparent (invisible)
- Alpha = 128 or 0.5: 50% transparent (see-through)
- Alpha = 255 or 1.0: Fully opaque (solid)
Note: Web (CSS) uses 0-1, while most other systems use 0-255 or 0-100.
Alpha in Different Formats
- CSS RGBA:
rgba(255, 0, 0, 0.5)— 50% transparent red - CSS HEX 8-digit:
#FF000080— 50% transparent red (80 hex = 128 decimal) - ARGB hex:
#80FF0000— same color, alpha first
Image Formats with Alpha Channel
- PNG: Full alpha support per pixel
- WebP: Alpha support
- GIF: Binary transparency (pixel is either fully transparent or fully opaque)
- JPG: No alpha channel
Use the Color Picker to set and preview alpha values when choosing colors for your project.