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Get your KDP files
right the first time.

6 × 9 in0.4504 in spine

The right cover size, spine width and margins for your book, plus a check before you upload. So KDP says yes the first time.

Browse the free toolsHow it works

Why KDP says no

Your book is ready.
KDP says no.

Most rejections come from a few small mistakes: the cover is the wrong size, the spine doesn’t match the page count, text sits too close to the edge, or a picture is blurry. Each one costs you days.

See the toolsHow it works
Wrong cover size
Spine too thin
Text too close to the edge
Blurry image

Tools

Free tools for every step.

Work out the sizes, download a template that already fits, then check your files before you upload. No sign-up.

  • Cover & spine calculator

    Tell us your book size and page count. Get the exact cover size and spine width.

    Open tool

  • Cover template generator

    Download a cover template that’s already the right size, ready for Canva or Photoshop.

    Open tool

  • 3D book mockup

    See your cover on a 3D paperback at its real size, and save a picture of it.

    Open tool

  • Margins calculator

    Find out how much space to leave around your text so nothing gets cut off.

    Open tool

  • Interior template

    A free page template with the safe margins already marked for your book size.

    Open tool

  • Bleed calculator

    See how big your pages must be when pictures go right to the edge.

    Open tool

  • Bleed vs no bleed

    A simple guide: do you need bleed, and what changes if you do?

    Open tool

What KDP wants

One cover file.
Three parts that must fit.

KDP wants the back, the spine and the front as one image. The spine’s width depends on your page count, so the whole file changes size with every book.

Novel
BackSpineFront
Novel6 × 9 in · 320 pages · spine 0.8 in

How it works

Four steps to a file KDP accepts.

Step 1

Tell us about your book

Pick the book size, type the number of pages and choose your paper.

6 × 9 in200 pagesWhite paper

Step 2

Get a template that fits

Download it, open it in Canva or Photoshop, and put your design on top.

Step 3

Check before you upload

Drop in your finished cover and interior. We point out anything KDP would reject.

Step 4

Fix it and upload

  • Wrong cover sizeResized
  • Missing bleedAdded
  • Spine too thinWidened
  • Text near the edgeMoved in
  • Your files never leave your browser
  • No uploads
  • No account
  • No cookies

Private by design.

Covers and manuscripts are read and checked on your own computer. Nothing is uploaded, so unpublished books stay private.

Browse the tools
  • UPLOADNONE
  • PROCESSINGIN BROWSER
  • ACCOUNTNOT NEEDED
  • COOKIESNONE

Every kind of book

Made for every book you’ll ever publish.

Novels, journals, coloring books, planners, cookbooks and picture books. If KDP prints it, these tools fit it.

Works with the apps you already use.

Templates open in any design app. The checker reads the PDF or image you export.

  • Canva
  • Adobe InDesign
  • Photoshop
  • Affinity Publisher
  • Microsoft Word
  • Google Docs
  • Vellum
  • Atticus
  • Illustrator
  • Procreate

Start free.

Calculators and templates are free, forever. Pro is for people who check a lot of files, and it’s coming soon.

See pricing

Free

$0

Forever

  • All calculators and templates
  • Cover and interior checker: 3 full checks a day
  • No sign-up

Pro

Popular

$6.99

Per month

  • Unlimited full checks
  • Check my book: cover and interior together
  • Cover fixer

Lifetime

$59

Pay once

  • Everything in Pro
  • Pay once, no monthly fee
  • New Pro tools as they arrive

For
self-publishers

Publishing your first book or your tenth? Get the sizes right and upload without the back and forth.

Start free

For cover
designers

Start every job from a template that’s already the right size, and show clients their files will pass.

See the tools