About FormatPaperback

Last updated: October 29, 2026

FormatPaperback checks your KDP paperback PDF the way KDP's reviewers do, fixes margin, gutter, trim-size and page-count problems in your browser, and builds a full-wrap cover with the exact spine width.

Why it exists

Most KDP paperback rejections aren’t about the writing. They’re a page number 0.1 in too low, a gutter that was right at 280 pages and wrong at 310, or a PDF exported at US Letter instead of 6 × 9. Fixing that usually means hours in Word or paying someone and waiting a day or two. FormatPaperback measures every page the way KDP’s reviewers do and fixes the geometry in minutes, without changing your pagination.

How it works

Everything happens in your browser: the PDF is rendered page by page, measured against KDP’s live area for your page count, and — if you choose — rebuilt at the exact trim size with one uniform scale. Your manuscript is never uploaded. Only the payment goes through our server and Stripe.

Who makes it

FormatPaperback is a small independent product operated by Tieli Liao (Singapore). It is not affiliated with Amazon or Kindle Direct Publishing. The rules it uses come from KDP’s public help pages and were last checked on 2026-10-29.

Contact

Questions, refunds, a file that doesn’t behave: hello@formatpaperback.com. We answer within two working days.