PNG Transparency Checker – Free Online Tool
Check whether a PNG or WebP contains transparent or semi-transparent pixels, with local alpha analysis and background previews.
Check Whether a PNG Is Really Transparent
Choose a PNG or WebP and the checker reads its alpha channel to determine whether any pixels are fully or partly transparent. This verifies the image data itself instead of relying on a checkerboard preview that may be baked into the picture.
See Fully Transparent and Semi-Transparent Pixels
The result separates alpha-zero pixels from anti-aliased or translucent pixels. Semi-transparent edges are common around logos, icons, shadows, and cut-out subjects even when most of the image is opaque.
Preview Transparency on Light and Dark Backgrounds
Switch between checkerboard, white, and dark previews to spot white halos, dark fringes, forgotten background pixels, and edge problems before using the asset on a website, presentation, design, or marketplace listing.
PNG and WebP Alpha Analysis in Your Browser
The browser decodes the image and inspects pixel alpha values locally. Images, filenames, previews, and pixel data are not uploaded to ToolsMint. Large images use a representative downscaled sample to keep the browser responsive.
What To Do When Transparency Is Missing
JPEG cannot store an alpha channel. Export the artwork as PNG or WebP with transparency enabled, then test the new file. If only the edges are partly transparent, inspect the asset on both light and dark backgrounds before delivery.
Frequently Asked Questions
Everything you need to know about the PNG Transparency Checker.
How can I tell if a PNG has a transparent background?
Inspect its alpha channel. This checker counts pixels with alpha values below fully opaque and previews the image on contrasting backgrounds.
Why does my PNG show a white background?
The white area may be real image pixels, or the app displaying the image may not show transparency clearly. Test the alpha channel and preview it on dark and checkerboard backgrounds.
Can JPEG images be transparent?
No. Standard JPEG does not support an alpha transparency channel. Use PNG or WebP for transparent backgrounds.
Are images uploaded?
No. Image decoding, alpha inspection, counts, and previews run locally in your browser.