KDP Manuscript Checker
A free, browser-based tool. Runs entirely in your browser — no sign up, nothing stored.
Book setup
Expected PDF page size (auto-detected from the file):
No bleed 8.270 × 11.690 in / 210.1 × 296.9 mm · Bleed 8.395 × 11.940 in / 213.2 × 303.3 mm
Your manuscript PDF
Drop a PDF here, or click to choose
Analysed in your browser — never uploaded.
Zerdly is not affiliated with Amazon or Kindle Direct Publishing. This tool checks common manuscript setup issues using public KDP guidance and cannot guarantee a book will be accepted. Always review your file in KDP Print Previewer before publishing. Your PDF is analysed in this browser and is never uploaded.
How to use this calculator
- Pick your trim size (6×9, A4, custom…), bleed setting and reading direction — the tool shows the exact PDF page size KDP expects.
- Drop your manuscript PDF onto the page. It's read entirely in your browser and never uploaded.
- Read the report: page size, margins and gutter, bleed, fonts and image resolution are each checked, with the measured value, the required value and a fix.
- Use the page-1 overlay (trim, margin and bleed guide lines) to see your set-out, and Copy or Download the full report as CSV.
How it works
For a no-bleed interior the PDF page should equal the trim size. For a bleed interior KDP wants the page 0.125 in wider and 0.25 in taller (0.125 in on the top, bottom and outside edge), so a 6×9 in book becomes a 6.125×9.25 in PDF and an A4 8.27×11.69 in book becomes 8.395×11.94 in.
It measures every page's box (1 in = 72 PDF points) against the expected size, then reads the text on each page to check margins (top, bottom, outside and the inside gutter, which grows with the page count) and to flag text smaller than 7 pt. For bleed books it renders page edges to check that artwork actually extends into the bleed instead of stopping at the trim line.
Finally it scans placed images for their effective resolution (pixels ÷ printed size, flagging under 300 dpi), checks whether fonts are embedded, and looks for interactive forms or comment annotations that don't belong in a print interior. Everything runs locally — the PDF never leaves your browser.
Worked example
A4 with bleed. Select A4 + Bleed and the tool expects 8.395 × 11.940 in. An 8.27 × 11.69 in (no-bleed) PDF is flagged with the exact re-export size, and the overlay shows where the trim, margin and bleed sit.
Common mistakes
- Choosing Bleed but exporting the PDF at the plain trim size — the page must include the extra 0.125/0.25 in.
- Letting a background image stop at the trim line on a bleed book — it must run past the edge by 0.125 in.
- Text or page numbers inside the safe margin, or too close to the gutter on a thick book.
- Not embedding every font, or placing images below 300 dpi at their printed size.
- Mixed page sizes or a two-page spread instead of single pages.
Frequently asked questions
What does the KDP Manuscript Checker check?
Page size vs your trim/bleed setting, inconsistent page sizes and two-page spreads, top/bottom/outside margins and the inside gutter, bleed (does artwork reach the edge), font size and embedding, image resolution, interactive forms and comment annotations, file size and encryption.
What size should my PDF be for A4 with bleed?
8.395 × 11.940 in (213.2 × 303.3 mm) — A4 trim (8.27 × 11.69 in) plus 0.125 in on the width and 0.25 in on the height.
Why does KDP add 0.125 in to the width but 0.25 in to the height?
Bleed is added to the top, the bottom and the outside edge (0.125 in each). That's 0.125 in across the width (outside only) and 0.25 in across the height (top + bottom). The inside/gutter edge gets none.
What margins does KDP need?
At least 0.25 in from the trim for a no-bleed book, or 0.375 in for a bleed book, on the top, bottom and outside. The inside (gutter) margin is larger and grows with the page count — about 0.375 in up to 150 pages, rising toward 0.875 in for very thick books.
How is the inside (gutter) margin decided?
By the binding, which depends on the page count rounded up to an even number: more pages need a wider gutter so text isn't lost in the spine. The checker uses your page count to pick the right gutter and which edge it's on (it flips for right-to-left books).
What is the bleed check looking for?
On a bleed book, any artwork meant to run off the page must extend past the trim line into the 0.125 in bleed. The tool renders page edges and flags pages where content reaches the trim but leaves white in the bleed zone — which would show as a thin white sliver after trimming.
Does it check fonts and image resolution?
Yes. It flags text under 7 pt, fonts that aren't embedded (including standard fonts like Helvetica), and images whose effective resolution is under 300 dpi at the size they're placed.
Can I export the report?
Yes — Copy CSV puts the full issue list on your clipboard, and Download CSV saves it as a spreadsheet you can work through.
Can this checker guarantee KDP approval?
No. It's a helpful preflight based on public KDP guidance and standard print logic, and it can't guarantee acceptance. Always confirm in KDP's own Print Previewer before publishing.
Does Zerdly upload my manuscript PDF?
No. The PDF is read and analysed locally in your browser — there is no upload, no server and no storage.
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