KDP Cover Checker
Check your paperback cover the way KDP does, before you upload. Pick your book details and your cover PDF: you get a pass, warning or fail for every rule, with your cover and the problem areas marked.
Your cover file
Checked on your computer. Files are never uploaded.
What we check
- Cover size, and by how much it’s off
- Bleed on every edge
- Spine width for your page count
- Picture resolution (300 DPI)
- Text inside the safe area
- Spine text and page count
- Fonts embedded
- A single page
Choose your cover file on the left to start. Results show here, with your cover and the problem areas marked.
How to use it
- 1
Enter your book
Pick the same book size, page count and paper you will choose on KDP. The spine width depends on them.
- 2
Choose your cover
Pick or drop your cover PDF (or a JPG or PNG before you export). It is read on your computer and never uploaded.
- 3
Fix and check again
Each check says what is wrong and how to fix it. The preview marks problem text and pictures in red.
What KDP checks on a paperback cover
KDP reviews every cover before a book goes live, and most rejections come from a short list of technical rules. This checker runs the same rules on your file, using the numbers from KDP’s own help pages and cover calculator.
Size, bleed and spine
A paperback cover is one flat sheet: back cover, spine and front cover, with 0.125 in of bleed on all four outside edges. For a 6 × 9 in book with 200 pages on white paper, the spine is 200 × 0.002252 = 0.4504 in, so the file must be 12.7004 × 9.25 in. If your file is 12.45 × 9 in, the bleed is missing. If it is 12.5 × 9.25 in, the spine was made for about 111 pages, not 200. The checker tells you which.
Even with the right size, a background can stop at the trim line instead of running to the edge. When the outer 0.125 in is white but the artwork just inside it isn’t, you get a warning: after trimming, a thin white line could show.
Pictures at 300 DPI
KDP asks for pictures placed at 300 DPI or more. The checker works out each picture’s real resolution from its pixels and the size it is placed at on the cover. A 3000-pixel-wide photo stretched across a 12.7 in cover is only 236 DPI. Below 300 DPI is a warning; below 200 DPI is a fail, because it will print visibly soft. The preview marks each low-resolution picture.
Text in the safe area
Text on the front and back cover must sit at least 0.125 in inside the trim lines and must not run into the spine. Spine text needs0.0625 in of space from each fold, because the fold can move that much when the book is bound. KDP only prints spine text on books of 79 pages or more, and its help page is unclear at exactly 79, so we recommend 80. Text smaller than 7 pt gets a warning.
Fonts, pages and file settings
- Fonts embedded: every font must be inside the PDF. Export with “embed all fonts” or a PDF/X preset; in Canva, use PDF Print.
- One page: the whole cover goes on a single page, not separate front and back pages.
- No security: locked or password-protected PDFs fail review.
- File size: under 650 MB, and ideally under 40 MB.
What it can’t check
KDP also checks that the title, author and ISBN on the cover match your book details, that text is readable against the background, and that there are no crop marks or template guides left in. Look at your cover in KDP’s previewer, and order a proof copy before you publish.
Questions and answers
What does the KDP cover checker check?
Cover size (and by how much it is off), bleed, spine width for your page count, the resolution of every picture, text inside the safe area, spine text and page count, embedded fonts, a single page, file security and file size.
Is my cover uploaded anywhere?
No. The file is read by your own browser, on your own computer. Nothing is sent to us or anyone else, and the check works even if you go offline after the page loads.
Can I check a JPG or PNG?
Yes, to check the size and resolution before you export. KDP itself needs the cover as a single PDF, so export to PDF at the same size once the checks pass.
How exact does the size need to be?
Exact. We allow 1/72 in (one PDF point) for rounding. Anything bigger is reported with the difference, for example “0.05 in too narrow”, because KDP checks the size against your page count and paper.
Why does it say my spine is wrong?
The spine width is page count × paper thickness: 0.002252 in per page on white paper, 0.0025 in on cream, 0.00235 in on groundwood and 0.002347 in on premium colour. If your file was made for a different page count or paper, the spine and the full width are off. The checker says how many pages your spine fits.
Does a pass mean KDP will accept my cover?
It means the file meets the rules KDP publishes. KDP also reviews things we can’t check, such as whether the title and author match your book details, so always look at KDP’s previewer and order a proof copy.
Why only 3 full checks a day?
The free plan gives 3 full results a day, counted in your own browser. After that you still see which checks pass or fail. Pro, coming soon, removes the limit.
Related tools
Cover & spine calculator
Tell us your book size and page count. Get the exact cover size and spine width.
Open toolCover template generator
Download a cover template that’s already the right size, ready for Canva or Photoshop.
Open tool