Fingerprint what KDP already accepted
Page count, trim, cover canvas, file hashes, fonts, rotations, image DPI, and interactive objects.
A small interior edit can break a live paperback.
Compare the currently accepted interior and cover against your planned revision before upload. Catch stale spine widths, wrong trim or bleed, mixed pages, swapped files, missing fonts, and low-resolution images.
Free beta · no account
Upload the accepted pair and the planned revision
PDF bytes are processed for this request and are not placed in application storage. Report access ends after 1 day; metadata is then removed by scheduled cleanup and can also be deleted immediately.
Before uploading: remove unnecessary personal data and upload only files you are entitled to process. This tool never connects to your KDP account.
Calculate what must change
The new page count drives spine width and the exact full-wrap cover width for the selected paper.
Stop stale or swapped uploads
A change report shows blockers, warnings, changed page positions, and the required upload dimensions.
Why four files?
Generic preflight validates files in isolation. Revisions fail at the relationship.
Example: adding two pages changes the spine. The revised interior may be valid and the old cover may still be a valid PDF—yet the pair no longer fits.
Revision Guard explicitly compares old pair → new pair and calculates the required cover delta.