Why do some pages in my KDP PDF have a different page size?
Short answer: KDP page size mismatches usually happen when bleed and no-bleed pages are mixed, inserted blank or backing pages use a different canvas, or source images were exported at inconsistent sizes. Keep every page in the interior PDF on the same KDP trim and bleed setup.
Why this causes KDP problems
A paperback interior is reviewed as one file. If some pages are 8.5 x 11 inches and others are bleed-sized, or if inserted pages use a different PDF box, KDP can treat the file as inconsistent. The problem may only appear on pages that were added after the artwork, such as blank pages, section dividers, or anti-bleed backing pages.
Recommended workflow
- Choose the exact KDP trim size once.
- Choose bleed or no bleed once for the interior PDF.
- Generate all artwork, blank, and backing pages on the same page canvas.
- Avoid combining PDFs exported from different tools unless you verify page boxes.
- Check the pages KDP lists in the error message.
- Preview the revised PDF in KDP Previewer.
Where Book Interior Kit fits
Book Interior Kit prepares imported artwork pages and optional backing pages from one selected KDP preset. It is useful when a folder of finished images needs to become one consistent paperback interior PDF.
What to check before publishing
- All pages have the same intended page size.
- Bleed pages and backing pages are not mixed with no-bleed pages by accident.
- Images are placed on a consistent 300 DPI page canvas.
- Page order is correct after filename sorting.
- The final interior is reviewed in KDP Previewer.
Book Interior Kit is independent software, is not affiliated with Amazon or KDP, and does not guarantee KDP approval.