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.
Drag to compare
Verify your PNG or WebP has a real alpha channel — not just a white or black background
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.
How it works
- Drop any PNG, WebP, or AVIF image
- The tool reads the alpha channel and reports whether any pixel has opacity less than 255
- A visual overlay highlights transparent and semi-transparent regions so you can see exactly where they are
Frequently asked questions
Why does my PNG look transparent in Windows Explorer but show as "no transparency" here?
Windows thumbnails sometimes display a white fill — the tool checks the actual alpha channel bytes in the file. If the tool reports no transparency, the image has no alpha channel.
Can I use this to check if a background removal result was successful?
Yes. Drop the output PNG here to confirm the background region has true transparency (alpha = 0), not a white fill.
Does it work with semi-transparent edges (soft alpha)?
Yes. Any pixel with alpha < 255 is counted as transparent, so soft edges from anti-aliasing or feathering are detected.
Related tools
Why it's different
Alpha channel verification done locally in your browser — no upload, no server. Detects true transparency vs. white/black backgrounds in seconds.
100% Private
Everything runs on your device using in-browser AI. Nothing is transmitted to any server — not the file, not metadata, not filenames.
True Alpha Channel
We export straight (non-premultiplied) alpha so transparent PNGs open with a real checkerboard in Photoshop and Figma — no black halos.
Free Forever
No paywall, no watermark, no premium tier. The full-quality AI is free, supported by non-intrusive ads.
Works Offline
Once loaded, the app and AI models cache locally. Process files without an internet connection. Installable as a desktop or mobile app.
Ready to try it?
Free, private, no signup.
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