Every tool you need to publish on KDP, in one place
Calculate your spine and cover, build your interior, write your listing and find out what is wrong with your file before Amazon does.
No account needed, and no upload: every file is read in your own browser and never leaves your machine.
All tools
- CalculatorGet the exact spine width and full cover size for any trim, paper and page count.
- InteriorsGenerate print-ready journals, planners, logbooks and grids as vector PDFs.
- CoversLay your artwork on a cover template with bleed, spine and barcode area marked.
- Pre-flightCheck an interior or cover PDF for the problems that get files rejected.
- Batch auditRun the pre-flight check on a whole stack of PDFs in one pass.
- Cover size calculatorFull cover dimensions, spine width, bleed, safety area and barcode position for any trim, paper and page count.No sign-up
- Margin calculatorThe minimum inside (gutter) and outside margins for your page count and trim, with and without bleed.No sign-up
- DescriptionWrite a book description in the HTML Amazon accepts, with a live preview.
- KeywordsFill the seven keyword boxes, with limits and duplicates checked as you type.
- CategoriesSearch the BISAC subject list to find the right categories for your book.
- AssistantAsk a question about KDP printing and get an answer about your own book.
- Knowledge hubLook up KDP's print requirements, from trim sizes to transparency.
- DashboardWhere every book you are working on is, and the next step each one needs.
- My booksKeep a library of titles, each with its own trim, paper, page count and listing.
- ExportDownload a book's interior, cover and listing together as one archive.
How a book gets through it
Five steps, in the order they happen. Each one is a tool in this app, and each reads the book you set up in the first.
Describe the book once
Trim size, paper and page count. That gives you the spine width and the full cover artboard, and every tool below reads the same specification — so the cover and the interior cannot disagree about the book.
Make the interior
Lined, dot grid, graph, planner, habit or storyboard pages, drawn as vectors with the fonts embedded and the gutter mirrored from left-hand page to right. Or skip it and bring your own PDF.
Lay out the cover
Place artwork on an artboard sized to your spine, with the bleed, the safety margin and the barcode keep-out zone drawn over it, then export a print-ready PDF.
Write the listing
The description in the HTML Amazon accepts, seven backend keyword slots and your BISAC categories — all kept on the book rather than in a scratch file.
Check it before Amazon does
Run the finished PDF through the pre-flight audit. It reports what it measured and what it could not, so a check that failed to read your file is never counted as one that passed.
A cover built for your exact page count
The spine is as wide as your pages are thick, so the cover cannot be set up until the page count is known. Give the calculator your trim, paper and page count and it returns the whole artboard.
- Full cover width and height, bleed included
- Spine width from your paper and page count
- Safe area for text on the front and back
- Where the barcode goes, so nothing important sits under it
What the pre-flight audit reads from your file
A check that could not read your file is never counted as one that passed.
Any PDF
File
The file parses as a PDF and its pages can be opened.
Font embedding
Every font the document draws with is embedded in the file. A missing font is substituted at the printer.
Encryption
The file is not password-protected or permission-restricted. KDP cannot open an encrypted interior and rejects it without reading the rest.
An interior
Page count
The number of pages sits inside the range the binding allows — 24 and up for a paperback, 75 for a hardcover, 800 at the top.
Page consistency
Every page is the same size. A single odd page is a rejection on its own.
Trim size
The page dimensions match one of the trim sizes KDP prints.
Bleed
Whether the pages carry the 0.125 inch bleed on the head, foot and outer edge, or are sized to trim.
Margins
Extracted text is measured against the outside and gutter margins your page count requires. Reported as not checked when a page holds no extractable text.
A cover
Cover safety margin
On a cover, that live text stays inside the safety margin measured in from the trim edge. Text outside it is at the mercy of the cut.
Barcode keep-out zone
That the barcode area on the back cover is clear. Amazon prints a barcode there — this is not a rejection, so a designer who fills it finds out from the printed book.
Spine text
That no text straddles the edge of the spine. The fold lands there, so a title that crosses it is bent around onto the front or back cover. KDP does not reject this either.
Made for self-publishers
Your files stay with you
Manuscripts and covers are read in your own browser. Nothing is uploaded to be checked or converted.
Correct answers are free
Every calculator, every cover dimension and every reason a file would be rejected is free, with no account needed.
One set of figures
The calculators, the checker and the guides read the same specification, so they cannot disagree about your book.
KDP guides
Why Amazon rejects a print file, and what to change — with the figures read from the same specification the tools use.
Rejection reasons
Interior
Cover
What it costs
A correct answer about your book will not sit behind a card form. The calculators, the guides and the pre-flight audit are free, and the free plan runs 5 audits a day and interiors up to 120 pages, with the rest listed in full on the pricing page. An account is free; it is what lets the app keep your books and your audits, and carry them between your own machines. Paid plans start at $5 a month, and they lift those limits rather than gate a correct answer.