Extract a PNG's Alpha Channel
Pull the transparency out of a PNG as a standalone grayscale image — white where the image is fully opaque, black where it's fully transparent, gray for everything in between. It's the mask designers and compositors work with. Runs in your browser; nothing uploads.
Drop PNG files here
Multiple files allowed
What the mask shows
Each pixel's alpha value becomes a shade of gray: 255 (fully opaque) is white, 0 (fully transparent) is black, and partial transparency lands in between. Drop a logo with a soft shadow and you'll see the shadow render as gray — exactly how much light it lets through.
What it's for
- Compositing — feed the mask to another tool as a selection or luminance matte.
- Debugging transparency — see precisely which pixels are see-through, and how much.
- Reusing a cutout shape — the alpha of one image as the mask for another.
FAQ
How do I get the transparency of a PNG as a separate image?
Drop the PNG above and click Extract — the alpha channel is rendered as a grayscale PNG you can download. It runs in your browser.
My image has no transparency — what do I get?
A solid white image, because every pixel is fully opaque (alpha 255). That itself confirms the file has no transparency.
How do I put the alpha back on later?
Recombining a mask with colour needs a compositing step in an editor; this tool extracts, it doesn't re-merge. To simply flatten transparency instead, see Remove alpha channel.
Part of: Work on one colour channel at a time
Split, look, then decide. Half of "the red is blown out" turns out to be the green channel once you actually see them separately.
- 1 Split RGB Three greyscale images, one per channel
- 2 Histogram Where each channel actually sits
- 3 Channel mixer Rebuild one channel out of the others
- 4 Extract alpha Pull the transparency out as its own image
- 5 Apply alpha mask Push a channel back in as transparency