Glossary
What is an alpha channel?
MarkdownWhat it is
Most images store red, green and blue for each pixel. An alpha channel adds a fourth value saying how opaque the pixel is.
Why it matters on a Mac
Logos, cutouts and icons need transparency to sit on any background. JPEG has no alpha channel, so saving a cutout as JPEG fills the transparent area with a solid color.
Which formats support it
PNG, TIFF, HEIC and WebP can store alpha. JPEG cannot. GIF supports only on-or-off transparency.
How Toolbox handles it
Remove Background lifts the subject out of a photo and saves a PNG, with a transparent, white or custom color background, using Apple's Vision framework on your Mac. Convert Images can write PNG, TIFF, HEIC or WebP.
Frequently asked questions
Why did my transparent background turn white or black?
The format you saved as probably has no alpha channel, such as JPEG.
Which format is best for transparency?
PNG is the most widely supported.
Does Remove Background work offline?
Yes. It runs on your Mac.
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