PNG transparency checker
Is that PNG really transparent, or is the checkerboard painted in? Drop it here and find out in a second, with the number of see-through pixels to prove it.
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What the answer means
Really transparent means some pixels have an alpha value below full: the picture has places with nothing in them, and whatever it is placed on shows through. A good cutout has two kinds: fully see-through pixels where the background was, and partly see-through ones along the outline, which is what lets hair and soft edges blend in rather than sit on top like a paper cutout. The alpha channel, in plain words explains why that second kind matters.
A fake means every pixel is solid and a grey and white checkerboard has been painted into the picture. It looks transparent in a thumbnail, and shows a checkered box on a slide, a shirt or a web page. The fake transparent PNG explains where they come from and how to avoid making one.
Not transparent means every pixel is solid and there is no grid either: an ordinary picture whose background is part of it.
The file and the pixels are two different questions
A PNG says in its header what kind of pixels it holds. Colour type 6 is RGBA, with an alpha value for every pixel; type 2 is plain RGB, with no room for transparency at all; a palette PNG can mark some of its colours as see-through. A WebP has a flag for the same thing. A JPG has nothing: the format cannot store transparency.
Room for transparency is not the same as using it. Plenty of apps export every PNG as RGBA out of habit, with every pixel at full opacity, and the file looks transparent-capable to anything that only reads the header. That is why the page shows the header line and the pixel count separately, and why the answer comes from the pixels.
How a painted checkerboard is found
Looking for grey and white is not enough: a product photographed on a white sweep is full of both. What a painted grid has, and a photo does not, is two neutral tones taking turns at one fixed length, along every row and down every column, with each pixel on the square the grid says it should be. The checker measures those runs, takes the commonest length as the size of a square, and then counts how many grid-coloured pixels fall where that grid puts them. A fake that was resized has squares that are not a whole number of pixels, and one saved as a JPG has slightly smudged tones; both are still found.
The background test, on the page
The quickest check anyone can do is to put the picture on a strong colour and look at the space around the subject. The buttons under the preview do that here: dark, white, mint, or a checkerboard. A real transparent picture takes on each background in turn. A fake keeps its squares on all of them. The preview starts on dark on purpose, because a checkerboard behind a painted checkerboard tells you nothing.
Fixing a fake
If there is no genuine copy to be found, treat the checkerboard as a background to remove. Remove the background opens the picture in the transparent background maker without it leaving your device, and the result is a PNG with a real alpha channel at the same size. The pixels along the outline were blended with grey and white squares when the fake was made, so check the edge on a dark colour, and if a light rim is left, move Edge shift a pixel or two below zero.
Guides that go further
Part of transparent pngs, explained. What each format is, when to use it, and what to do when a file will not open.
- The fake transparent PNG: how to spot one, and how to fix itA fake PNG has the grey and white checkerboard painted into its pixels. How to spot one before you download, why they exist, and how to fix the one you have.
- What is a transparent background, really?A transparent background is empty pixels, not white ones. How alpha works, why editors show a checkerboard, and which formats keep it: PNG, WebP, AVIF, not JPG.
- Transparent PNG: what it is, where it works, and where it failsA transparent PNG stores see-through pixels, not a checkered background. How to tell a real one, where transparency survives, and where it turns white.
- Why your PNG shows a black or white background (and how to keep it transparent)Why is my PNG not transparent? Why a transparent PNG turns black or white in viewers, WhatsApp, Instagram, email and Office, and how to keep the transparency.
- Alpha channel, in plain wordsWhat an alpha channel is: the fourth value in each pixel that sets how see-through it is. 8-bit alpha, soft edges, straight versus premultiplied, no maths.
Questions
How do I check if a PNG is transparent?
Drop it on this page. It reads every pixel's alpha value and says how much of the picture is fully see-through, how much is partly see-through along the edges, and how much is solid. It also reads the file's header, which says whether the format as saved can hold transparency at all. Nothing is uploaded: the check runs in your browser.
What is a fake transparent PNG?
A picture with the grey and white checkerboard painted into its pixels. Editors draw that grid on screen to show where a picture is empty, and a screenshot or a preview saved from an image site keeps it as ordinary grey and white squares. It looks transparent in a thumbnail and shows a checkered box everywhere you use it. This page spots the grid and tells you the size of its squares.
How does it tell a painted checkerboard from a white background?
It looks for a grid rather than for two colours. A product photo on white has plenty of white and light grey, but not two neutral tones alternating at one fixed length across the rows and down the columns, with the pixels sitting on the right squares of that grid. A painted checkerboard does, even after it has been resized or saved as a JPG.
Can a JPG be transparent?
No. JPG has no alpha channel, so every pixel in a JPG is solid. A JPG that looks transparent in a search result has a checkerboard painted into it. WebP, PNG, AVIF and GIF can all store transparency, and this page reads WebP's and PNG's headers to say whether a particular file does.
The file has an alpha channel but the page says it is not transparent. Why?
Because having room for transparency is not the same as using it. A PNG saved as RGBA can still have every pixel at full opacity, which is common when an app exports everything with an alpha channel by habit. The header line and the pixel count are shown separately for exactly that reason.
How do I fix a fake transparent PNG?
Click Remove the background. The picture opens in the background remover on this site, still on your device, which treats the checkerboard as any other background and saves a PNG with a real alpha channel. If a light rim of the grid is left along the outline, move Edge shift a pixel or two below zero.
Is my picture uploaded?
No. The file is read by your browser and checked with code that runs on this page. Nothing about it is sent anywhere, and once the page has loaded it works with the network switched off.
Your files never leave this device
Most online converters upload every file to a server, convert it there and keep it for a while. Here your browser decodes and encodes the picture itself, so there is nowhere for the file to go. You can check it: load this page, switch the browser to offline, and convert a file. How to check a site is not uploading your photos.