Inspect image transparency
Count alpha pixels and inspect a transparency mask. Processing stays in your browser.
Inspect an image
Drop an image here
PNG, JPG, WebP or GIF · up to 15 MB
Transparency mask
Clear pixels use the transparent color, partial alpha uses the translucent color, and solid pixels use the opaque color.
A checkerboard in an editor does not prove that the file has alpha. This checker reads each decoded pixel. Animated GIFs are checked from their first frame.
What this tool does
Inspect actual pixel alpha rather than guessing from a checkerboard or a filename. The result separates clear, partly transparent and solid pixels.
How to use it
- Choose an image and read the counts for transparent, translucent and opaque pixels.
- Pick colors for the three groups to make the alpha mask easier to inspect.
- Optionally show actual translucency in the mask, then download the mask as PNG.
Understand the controls
- Pixel groups
- Alpha 0 is transparent, alpha 1–254 is translucent, and alpha 255 is opaque. A JPEG decodes as fully opaque.
- Mask colors
- These colors visualize the alpha categories; they do not change the source image.
Example
Before placing a logo over a dark background, inspect its mask to see whether the edge really contains partial transparency.
Files and limits
One file up to 15 MB, 8192 px per edge and 32 million pixels. Animated GIFs are inspected from their first frame.
Frequently asked questions
How are pixels classified?
Alpha 0 is transparent, alpha 1–254 is translucent, and alpha 255 is opaque.
Does a JPEG have transparency?
No. JPEG has no alpha channel, so decoded JPEG pixels are opaque.
Is my image uploaded?
No. Its pixels are checked locally in your browser.