KDP tools / Interior preflight

KDP Interior PDF Preflight

Your manuscript is laid out and exported. Before it goes to KDP, find out what the file itself proves, what conflicts with Amazon’s requirements, and — just as plainly — what this inspection could not establish. Nothing is uploaded; the PDF is read in this tab.

  • Read in your browser — nothing uploaded
  • Says what it could not verify, instead of showing a tick
  • Free, no account
Your finished interior PDF

or drop it here. Up to 64 MB. It is read in this tab — there is no upload on this page, and no text is extracted from your manuscript.

What comes back

Four answers, kept apart: what needs fixing, what is worth reviewing, what could not be verified, and what was measured and satisfied. Page size and rotation on every page, the exact extent, whether fonts travel inside the file, and the print resolution of each image over the inches it is actually painted across.

Where something cannot be established honestly it is reported as unverified and kept out of the passes — a checker’s silence reads as approval, and this one does not stay silent.

Reading the file, and stopping where the file stops

A finished PDF is evidence. This reads the evidence and refuses to guess the rest.

An interior PDF carries its own facts. Every page states a physical size and a rotation; the page tree states an exact count; each page lists the fonts it draws with and whether the typeface itself travels inside the file or is merely named; each raster image states its pixel dimensions, and the page description states the inches it is actually painted across. Those are read here, in your browser, with the same parser the rest of this site uses — the file is never sent anywhere, and no text is extracted from it at any point.

What makes a checker trustworthy is not the length of that list. It is what happens at the edge of it. Some design tools nest artwork inside a reusable object with its own coordinate system; some pages compress their content in a way this reader deliberately refuses to guess at; a very long book stops being deeply inspected after 828 pages so a browser tab survives the read. In every one of those cases the honest answer is “we could not establish this”, and it is reported as its own outcome — never folded into the passes, never shown as a tick, never counted as evidence that nothing is wrong.

So a report here has four separate answers rather than two: what needs fixing, what is worth reviewing, what could not be verified, and what was genuinely measured and satisfied. Page size is compared against Amazon’s published interior geometry, extent against the overall 24–828 paperback catalogue bounds, and raster artwork against 300 PPI at the size it is actually placed. Amazon’s rules behind all of it were last checked against their published help pages on 2026-08-27. Exact page-count eligibility depends on trim and print option; add your KDP setup here to check that combination.

What it reads

Every row below is read out of your own file, or reported as unverified.

  • One page size, all the way throughEvery page measured after rotation, and the ones that disagree with the rest named by page number. A stray letter-sized page in a 6 × 9 book is a common export accident.
  • Which KDP geometries the page size fitsEvery standard KDP interior geometry your measured page is consistent with, bleed and no-bleed. Offered as candidates, never as a chosen trim — the file does not know which you meant.
  • Fonts embedded, not just namedA typeface that is named but not carried inside the PDF is substituted wherever it prints, and the line breaks come back wrong. Where the resource graph could not be read completely, that is said instead.
  • Print resolution of your artworkEach raster image's pixels over the inches it is actually painted across, read from the page description rather than guessed from the page size, and compared against 300 PPI.
  • Overall paperback page-count boundsThe exact page count, KDP’s effective even count, and whether that lands inside the overall 24–828 paperback catalogue bounds. Exact eligibility depends on trim and print option; add your KDP setup to check that combination.
  • Pages rotated after exportA page rotated after the fact stores one size and prints another, which print software disagrees about more often than it should.
  • The file against the setup you declareOptional. Add the trim, extent, paper and bleed you are publishing at and the file is compared with it directly — page size, eligibility, and whether the extent you declared matches the one in the PDF.
  • How much of the file was actually readWhich pages could be inspected completely and which could not, stated up front, so no silence on this page can be mistaken for a clean result.

And what it cannot tell you

  • It cannot tell you whether your margins are right, whether your text sits inside the gutter, or whether artwork reaches the bleed. All three need the position of every mark on the page, which means rendering it. Set the margins before you lay out, with the KDP Margin Calculator.
  • It cannot repair anything. There is no resize, no reflow, no font embedding, no colour conversion and no image upscaling here. A finished interior is corrected in the document it was exported from, and every next step on the report says so.
  • It cannot decide your trim for you. The page dimensions are compared against Amazon’s geometry and every match is reported, but a 6 × 9 no-bleed page and a page that merely measures 6 × 9 are the same rectangle. Only you know which book this is.
  • It cannot give an Amazon verdict. It measures geometry and file structure against Amazon’s published specifications; KDP’s Print Previewer and its human reviewers are the only authorities on whether a book is accepted.
  • It does not read your words. No text is extracted, no content is interpreted, and nothing about the manuscript leaves the browser tab.
FAQ

Frequently asked

Is my manuscript uploaded anywhere?

No. The PDF is read by your own browser and inspected there — there is no upload step on this page, no account, and nothing about your book is sent to us or stored by us. Page numbers, dimensions and file names stay in the tab; closing it is all it takes to be rid of them.

Do I have to fill in my trim size and page count first?

No, and the page is built so you do not. Drop the PDF in and you get the file’s own evidence straight away: the page size, the geometries it is consistent with, the extent, the fonts, the artwork resolution and everything the inspection could not reach. Declaring your setup afterwards adds one thing — a direct comparison against the book you believe you are publishing.

It says something “could not be verified”. Is that a problem?

It is neither a problem nor an all-clear, and that is exactly why it has its own section. Some PDFs nest artwork or fonts inside reusable objects this reader does not open, some compress content in ways it refuses to guess at, and a very long book stops being deeply inspected partway through to keep the browser safe. Where that happens, the fact is unknown rather than fine. Look at those pages yourself in KDP’s Print Previewer.

My file has no blockers. Does that mean KDP will accept it?

No, and nobody can offer you that. It means no blocking issue was found in the checks that could be completed on this file. It says nothing about your margins, your reading order, your metadata, your cover, or what a human reviewer makes of the book. Amazon retains final review — look at the interior in KDP’s Print Previewer and order a proof copy before you launch. Amazon’s published rules behind these checks were last verified on 2026-08-27.

How is this different from the KDP Margin Calculator?

The margin calculator runs before you lay the book out: you tell it the trim, extent and paper, and it gives you the page size, the inside gutter and the other minimum margins to set in your layout program. This page runs after: it takes the PDF that came out the other end and tells you what is actually in it. Most authors want both, in that order.

Why does it not just fix my PDF?

Because the corrections that matter cannot be made honestly in a finished file. Embedding a typeface that was never included means having the typeface; resizing pages moves every margin and every line of text inside them; resampling an image cannot add detail that was not captured. Each of those would produce a file that looks repaired and prints wrong. The fix belongs in the document the PDF was exported from, which is why each finding names an export setting or a page to return to.

How big a file can it read?

Up to 64 MB. Past that a browser cannot safely hold the file and the objects needed to parse it, so it is refused before anything is read rather than crashing the tab. Deep resource inspection also stops after 828 pages — the exact page count and every page’s size are still measured, and anything not inspected is reported as unverified rather than passed.

It found pages that are a different size. What now?

Open the source document at those page numbers. A single odd page is nearly always a section break with its own page setup, a landscape table, or a scanned insert placed at its own dimensions. Set them to the book’s page size and export again — KDP prints one interior at one page size.