Check a PDF
How many pages, what size, and above all: are your fonts embedded? The file is read inside your browser.
This application is served by KNPLIV and runs sandboxed: it cannot read your sign-in details, store anything on your device, or send in the background what you type into it. Everything is gone when you leave the page. Like everything published here, it was read over before going online.
The commonest reason an interior is refused by Amazon KDP is also the only one an author cannot see by eye: a font that was not embedded in the file. The PDF opens perfectly on your machine — because the font is installed on it — and sets badly at the printer’s, who does not have it.
This tool opens the file and reads its structure. It tells you:
how many pages there are, and whether the structure announces a different number;
the page size in inches and in millimetres, whether it matches a trim size taken from Amazon, and whether every page is the same size;
the list of fonts used, and for each one whether it is embedded, whether it is one of the fourteen standard PDF fonts — which do not have to be — or whether it is missing;
whether the file is password-protected, which Amazon refuses;
whether it declares a trim area, that is, whether it was prepared for bleed.
What it does not do, and does not claim to do: judge your margins, your images or your layout. That would mean composing the page. Amazon remains the only judge, and says nothing until you upload.
Your file does not leave your device. This page has no network access at all: the site’s security policy forbids it.