How to check your KDP interior
- Choose your KDP setup. Pick the trim size, ink and paper, and bleed setting you chose (or will choose) on KDP's paperback content page.
- Drop in your interior PDF. Drag your manuscript PDF onto the checker. It is read inside your browser and never uploaded.
- Read the report. Each KDP rule shows as OK, Check or Fix, with the pages involved and what to change. Click a page number to see it with the trim, margin and gutter lines drawn on.
- Fix and re-check. Correct the flagged pages in your layout program, export again and drop the new PDF in. Download the report to keep with your KDP setup.
What the checker tests
| Check | KDP rule |
|---|---|
| Page size | Every page equals the trim, or trim + 0.125" × 0.25" with bleed. No mixed sizes, no spreads. |
| Page count | 24 minimum (72 for standard color). Maximum depends on trim and paper (table below). |
| Gutter | 0.375" to 0.875" on the binding side, by page count, mirrored on left and right pages. |
| Margins | Text at least 0.25" from the trimmed edge (0.375" on bleed books). |
| Bleed | Art that touches the page edge needs a bleed-size PDF and the Bleed setting on KDP. |
| Fonts | All fonts embedded in the PDF. |
| Text size | 7 pt minimum. |
| Images | 300 DPI at the size they are printed. |
| Blank pages | No long runs of blank pages inside the book or at the end. |
| Ink | Color pages in a black-ink book print in grayscale. |
| File | No password or security, no comments or form fields, 650 MB or less. |
KDP page limits by trim size and paper
The minimum is 24 pages for black ink and premium color, and 72 for standard color. The maximum depends on the trim and paper. KDP counts every page of your PDF, blank ones included, and rounds an odd count up by one.
| Trim | White | Cream | Standard color | Premium color |
|---|---|---|---|---|
| 6" × 9" | 24-828 | 24-776 | 72-600 | 24-828 |
| 8.5" × 11" | 24-590 | 24-550 | 72-600 | 24-590 |
| 7" × 10" | 24-828 | 24-776 | 72-600 | 24-828 |
| 5" × 8" | 24-828 | 24-776 | 72-600 | 24-828 |
| 5.06" × 7.81" | 24-828 | 24-776 | 72-600 | 24-828 |
| 5.25" × 8" | 24-828 | 24-776 | 72-600 | 24-828 |
| 5.5" × 8.5" | 24-828 | 24-776 | 72-600 | 24-828 |
| 6.14" × 9.21" (15.6 × 23.4 cm) | 24-828 | 24-776 | 72-600 | 24-828 |
| 6.69" × 9.61" (17 × 24.4 cm) | 24-828 | 24-776 | 72-600 | 24-828 |
| 7.44" × 9.69" (18.9 × 24.6 cm) | 24-828 | 24-776 | 72-600 | 24-828 |
| 7.5" × 9.25" | 24-828 | 24-776 | 72-600 | 24-828 |
| 8" × 10" | 24-828 | 24-776 | 72-600 | 24-828 |
| 8.25" × 6" (landscape) | 24-800 | 24-750 | 72-600 | 24-800 |
| 8.25" × 8.25" (square) | 24-800 | 24-750 | 72-600 | 24-800 |
| 8.5" × 8.5" (square) | 24-590 | 24-550 | 72-600 | 24-590 |
| 8.27" × 11.69" (A4) | 24-780 | 24-730 | Not offered | 24-590 |
The most common reasons KDP rejects an interior
- The PDF is the wrong size. A 6 x 9 book exported as US Letter, or a bleed book exported at trim size. The checker tells you which trim your file was really made for.
- Text in the gutter. Page numbers and headers placed with equal left and right margins end up too close to the binding on half the pages. Use mirrored margins.
- Art to the edge without bleed. A border, background or photo that touches the edge of a no-bleed page gets cut unevenly when the book is trimmed.
- Fonts not embedded. Some word processors and online editors save PDFs that rely on the reader's fonts. Export as PDF/X-1a or with "embed all fonts".
- Low-resolution images. Images pulled from the web are often 72 DPI. They pass upload but print soft.
What a file check cannot see
The checker reads the real geometry of your PDF, but some things need human eyes: text that is part of an image, thin lines inside artwork, whether an upscaled image is actually sharp, and whether a full-bleed photo crops something important. KDP's Print Previewer and a proof copy remain the final word. The cover is a separate file with its own size; get it from the cover size calculator.
Building a puzzle or activity book? The Book Studio lays out every page inside these margins automatically and runs the same KDP checks before you export. The margin rules themselves are explained, with a live spread, in the margin calculator.
Rules checked against Amazon KDP's paperback help pages on 10 October 2026. PuzzlePage is not affiliated with Amazon.
Frequently asked questions
What does the KDP PDF checker check?
Page size against your trim and bleed setting, mixed page sizes and two-page spreads, page count limits for your trim and paper, text in the gutter and outside margins, art that runs to the edge without bleed, embedded fonts, text under 7 pt, images under 300 DPI, long runs of blank pages, color pages in a black-ink book, comments and form fields, and password protection.
Is my PDF uploaded anywhere?
No. The PDF is opened and measured by your own browser, so a manuscript never reaches our servers and large files check without an upload wait. We count only the outcome (such as the verdict and page count) in anonymous usage statistics, and if you ask for the report by email we keep the file name and verdict with your address.
Which trim sizes does it support?
All 16 standard KDP paperback trims: 5 x 8, 5.06 x 7.81, 5.25 x 8, 5.5 x 8.5, 6 x 9, 6.14 x 9.21, 6.69 x 9.61, 7 x 10, 7.44 x 9.69, 7.5 x 9.25, 8 x 10, 8.25 x 6, 8.25 x 8.25, 8.5 x 8.5, 8.27 x 11.69 (A4) and 8.5 x 11, each with or without bleed. It also tells you which trim your PDF was actually made for.
Is it free? Do I need an account?
It is free. Without an account you can check one book and download its report by entering your email. With a free PuzzlePage account, or any paid plan, you can check as many books as you like and download every report directly.
What size should my KDP interior PDF be?
Without bleed the PDF page is exactly the trim size, for example 6 x 9 inches. With bleed it is 0.125 inch wider and 0.25 inch taller, for example 6.125 x 9.25 inches, because bleed is added to the outside edge and to the top and bottom but never to the binding edge.
How big does the KDP gutter need to be?
The inside margin depends on page count: 0.375 inch for 24 to 150 pages, 0.5 inch for 151 to 300, 0.625 inch for 301 to 500, 0.75 inch for 501 to 700 and 0.875 inch for 701 to 828. Outside, top and bottom margins must be at least 0.25 inch, or 0.375 inch on a bleed book.
Does it work for Amazon Australia, the UK and other marketplaces?
Yes. KDP uses one set of paperback interior rules for every marketplace it prints for, including Amazon.com.au, Amazon.co.uk, Amazon.ca and the European stores, so the same check applies wherever you publish. The metric trims common outside the US are included: A4 (21 x 29.7 cm), 15.6 x 23.4 cm (6.14 x 9.21 in), 17 x 24.4 cm (6.69 x 9.61 in) and 18.9 x 24.6 cm (7.44 x 9.69 in).
If the checker says OK, will KDP accept my book?
It catches the formatting problems KDP rejects most often, but KDP's own review is final and also judges things no file check can, such as text inside images, content quality and your cover. Always open KDP's Print Previewer and order a proof copy before you publish.