Free tool · runs in your browser
Is your PNG actually transparent?
Choose a PNG and this page reads the alpha value of every pixel, then tells you whether the image is transparent, partly transparent, or fully opaque, along with its dimensions. The file is read on your device and never uploaded.
- Free
- No upload
- No account
- Every pixel counted
Useful when a cutout shows a white box in Keynote, Canva, or a listing, or when you are not sure a downloaded “transparent PNG” is the real thing. A checkerboard you can see in a thumbnail is not proof; it may be painted into the pixels.
PNG transparency checkerRead on this device
or drop one here · up to 60 MB and 50 megapixels
Need to make a transparent PNG from a photo? See a real cutout from Background Remover’s engine, or get the iPhone app ($3.99 once).
This checker needs JavaScript to read the file in your browser. Without it, place the PNG over a brightly colored layer in any design app: if the color shows around the subject, the file is transparent. More ways to check.
The page counts alpha values only. It does not send the image, its name, or its dimensions anywhere, and it stores nothing.
Reading the result
What each answer means.
PNG can store an alpha value from 0 (fully clear) to 255 (fully solid) for each pixel. The checker counts how many pixels fall into each group.
Transparent
Some pixels are fully clear. A cutout with its background removed usually has clear corners and partly clear pixels along soft edges such as hair and fur.
Partly transparent
Nothing is fully clear, but some pixels are see-through. Common in glows, shadows, and watermarks. A faint value may still look solid.
Opaque
Every pixel is solid. The file may still be a PNG, and may even have an alpha channel, but the background is part of the image.
Not a PNG
The data inside is JPEG, HEIC, WebP, or something else. Renaming a JPEG to .png never adds transparency; export the image again as PNG.
Sample cutout · with its source
A transparent PNG made by the app’s engine.
This chair cutout came from Background Remover: PNG Cutout’s subject-mask code, the same Apple Vision provider the app uses. The openings under the arms came out see-through instead of filled in, though the smaller left one keeps some faint, partly transparent pixels (switch the checker to Alpha map to see them). Download the original file and run it through the checker above, or drop it into your own design app.
Make your own on iPhone or iPad
Cut out the subject, fix edges by hand, export a full-size PNG.
$3.99 once no subscription no in‑app purchases
The checker on this page stays free and works without the app.
Why a PNG can look transparent and not be
- A screenshot of a checkerboard records the gray and white squares as ordinary solid pixels. The checker will report it as opaque.
- A JPEG renamed to .png still contains JPEG data, which has no alpha channel. The checker reads the file’s signature, not its name.
- An export on White makes a valid PNG with a solid background. PNG allows transparency; it does not require it.
- A messaging app or uploader may convert your PNG to JPEG on the way. Check the file you received, not just the one you sent.
How the checker works
The page reads the file with your browser’s File API. It first checks the PNG signature, header, and every chunk checksum, so damaged or incomplete files are reported instead of guessed at. Your browser then decodes the pixels, and the page counts every alpha value in tiles. Nothing is uploaded, saved, or added to the address bar, and choosing a file sends no analytics event. Optional Google Analytics on this website records page visits only if you allow it, and it never receives your image.
Limits
- PNG files only, up to 60 MB and 50 megapixels (16,384 pixels per side). Larger files are refused before decoding to reduce memory use. Files near these limits may still exceed a mobile browser’s memory; use a smaller PNG if the tab cannot complete the check.
- Animated PNGs: only the first frame is checked.
- 16-bit PNGs are measured at 8-bit precision, so a pixel at 99.8% opacity or more counts as opaque.
- It answers whether pixels are clear. It cannot judge whether the right parts were removed; look at the preview on light and dark for that.
Questions
About the checker.
Is the checker free?
Yes. There is no sign-up, limit, or watermark, and you do not need the app. Background Remover: PNG Cutout is a separate $3.99 iPhone and iPad app for making cutouts.
Is my image uploaded?
No. The file is read and decoded inside this browser tab. The page makes no request with your image, its name, or its dimensions, and keeps nothing after you leave or press Clear.
Why does my “transparent” PNG show a white background?
Either the file is opaque (the checker will say so), or the app showing it puts a white backing behind transparent pixels. If the checker says transparent, test the file over a colored layer in a design app, and check that the destination does not convert it to JPEG. Transparent PNG guide.
Can it check JPEG, HEIC, or WebP files?
It identifies them and tells you the file is not a PNG. JPEG and HEIC photos from a camera have no transparency. WebP can store transparency, but this checker only measures PNG files.