Quick guide
How to check an image for transparency
- Add your image. Choose a file, drop it onto the tool, or paste it.
- Read the result. See whether any pixels are fully or partially transparent.
- Inspect the edges. Switch views or download the grayscale alpha mask.
Is the checkerboard real transparency?
A checkerboard usually represents transparency inside design software, but it can also be permanently saved as part of an image. If this checker reports that every pixel is opaque, any checkerboard you see is baked into the image and will not disappear when you place it over another background.
What is an alpha channel?
Alpha describes each pixel's opacity from 0 to 255. An alpha value of 0 is fully transparent, 255 is fully opaque, and a value between them is semi-transparent. Soft shadows and anti-aliased edges commonly use partial alpha values.
PNG, WebP, GIF, and JPEG
PNG and WebP can store smooth, partial transparency. GIF can use a single transparent color, so its edges are usually either fully visible or fully transparent. JPEG does not support transparency and will always be reported as opaque.
Your image remains private
The browser decodes and checks every pixel locally. ToolQuill does not send the file to a server. The download button creates the alpha mask in your browser, and Reset removes the working image from the page.
Frequently asked questions
Why does my PNG have no transparency?
PNG supports transparency, but a PNG is not automatically transparent. An export can flatten the artwork against white or even save a checker pattern into the pixels. This tool checks the decoded pixel values rather than relying on the file extension.
What does the soft-edge view show?
It highlights every semi-transparent pixel in pink. Use it to locate feathered selections, soft shadows, anti-aliased outlines, or faint halos that may be difficult to see on a checkerboard.
Does the checker modify my image?
No. Preview controls change only what is drawn on the page. The original file is not edited, compressed, or uploaded.