Glossary
Alpha Transparency
Also: alpha channel · transparent background · transparency
Alpha transparency is a channel that stores how opaque each pixel is, letting parts of an image be fully or partly see-through. PNG, WebP, AVIF, and GIF support it; JPG does not.
Reviewed by Chad Solomon · Updated June 2026
Explained
How the alpha channel works
The alpha channel adds a fourth value to each pixel alongside red, green, and blue, recording opacity from 0 (fully transparent) to 255 (fully opaque). Partial values create smooth, anti-aliased edges, so a logo can sit cleanly on any background.
Explained
Which formats support transparency
Four common formats support transparency: PNG (full 8-bit alpha), WebP (full alpha), AVIF (full alpha), and GIF (1-bit on/off only). JPG and JFIF have no alpha channel — converting a transparent image to JPG fills the transparent areas with a solid color, usually white or black.
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Questions
Frequently asked
- Does JPG support transparency?
- No. JPG has no alpha channel, so transparent areas become a solid background color when you convert to JPG. Use PNG or WebP to keep transparency.
- Which format keeps a transparent background?
- PNG, WebP, and AVIF all preserve transparent backgrounds. PNG is the most widely supported choice for logos and graphics.
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