True-alpha verdict
The result comes from pixel data, not a filename extension or visual guess.
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.
Watch the workflow
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
Alpha diagnosis
Checkerboard appearance is not proof of transparency
The scan reads actual alpha values and distinguishes fully opaque pixels, partial edges, and genuinely transparent regions.
RGBA scan
What is inspected
Partial-edge visibility
Semi-transparent antialiasing is reported separately from fully clear pixels.
Next-step guidance
Opaque files can move to background removal; valid cut-outs can move to compositing.
Know before you process: JPEG cannot store alpha. A checkerboard baked into JPEG pixels is still an opaque background.
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