Check a product photo against a marketplace's rules

No, and nothing on this page says so. It means the picture satisfies the rules as this page measures them. Marketplaces do not publish their tolerances, they change them without notice, and several of the figures here come from independent references rather than from the platform itself - the report says which for each one. Treat a failed check as worth fixing and a passed one as one fewer thing to worry about.

By looking at the border of the picture rather than at the whole of it, and comparing against 255, 255, 255 exactly, because that is how the rule is written. The border matters: a photograph of a white shoe on a grey backdrop is mostly white by area and fails the rule in the only place the rule is about. The report gives the share of the border that is exactly white and the share that is close to it, so an almost-white backdrop reads as an almost-white backdrop rather than as a flat no.

As the box around everything in the picture that is not background, divided by the whole frame. That is deliberately not a count of product pixels: a bracelet photographed flat covers very little of the picture and fills the frame completely, and a rule about how much of the frame the product occupies is about extent. Anything within about 4% of white counts as background for this purpose, so a soft shadow still counts as part of the subject.

Because they cannot. Whether the photograph shows the product you are actually selling, whether there is a logo or added text on it, whether it is in focus - none of these is answerable from the bytes of a file, and a page showing a column of green ticks while silently skipping them would be telling you your listing is fine on the strength of the easy half. They are listed, in the marketplace's own terms, marked as needing your eyes.

Because they genuinely do, and copying one platform's rules onto another is the most common mistake in this area. Amazon states a pure white background and 85% frame fill for a main image; Shopify states neither, so a white background there is a choice about how your store looks rather than something you have been told to do. This page keeps them apart and does not invent a rule for a platform that has not stated one.

No. The picture is decoded and measured by your own browser and no file is produced at all, so there is nothing to upload and nothing is sent. A content security policy the browser enforces stops this page reaching another domain, which is worth saying on a page about commercial product photography that has not been published yet.