PNG Transparency Explained (The Alpha Channel)
PNG images can have transparent areas thanks to an alpha channel. Learn how transparency works, why JPG can't do it, and which format to choose.
PNG supports transparency through an alpha channel — an extra value per pixel that sets how opaque it is, from fully clear to fully solid. That is why a PNG logo can sit on any background without a white box around it.
What the alpha channel does
Each pixel stores red, green and blue plus an alpha value. Alpha 0 is fully transparent, 255 is fully opaque, and values in between are semi-transparent — useful for soft shadows and smooth edges.
Why JPG can't be transparent
JPG has no alpha channel, so it fills every pixel with a solid color. Save a transparent image as JPG and the see-through areas become white (or black). For transparency, use PNG or WebP instead.
When to use transparent PNG
Logos, icons, stickers and any graphic that must overlay other content. For photographs with no transparency, JPG or WebP give smaller files.
Work with it
Convert to PNG to keep transparency with the image converter, or embed a small transparent image as a data URI with image to Base64. Related: PNG vs JPG vs WebP.