Free Tool
Check PNG Transparency
Upload a PNG or WebP to verify it has a real alpha channel — not just a white or black background pretending to be transparent.
Drop a PNG or WebP here
or click to browse
How this works
This tool reads your image file using the browser's Canvas API. It samples 500 random pixels and checks whether any have alpha values between 1 and 254 (partial transparency). It also checks for common false-transparency patterns: all-white or all-black backgrounds with no actual alpha channel.
Your image never leaves your device — all analysis is done locally in the browser.