Free KDP Cover Checker: Fix Wrong Size Errors Fast
Upload the cover image you tried to submit and see why KDP still flags it. This preflight helps you spot KDP cover wrong size issues, expected cover size mismatches, KDP bleed error risk, KDP spine width error risk, and the Canva exports that trigger KDP Print Previewer errors.
Last updated: 2026-03-13
Expected full wrap
Size
12.700 × 9.250 in
322.6 × 235 mm
Target pixels at 300 DPI
3,810 × 2,775 px
Current spec
Upload an image and run a KDP preflight
1. Book specs
2. Upload your current cover file
No file selected yet
Preflight result
Upload an image to start the preflight
Uploaded file
No file selected yet
JPG, PNG, WEBP, or PDF
Expected full wrap
12.700 × 9.250 in
322.6 × 235 mm · 3,810 × 2,775 px
Detected asset type
Waiting for a file
Upload an image to classify the asset
Estimated print DPI
Pending
We estimate print DPI after reading the image
What the preflight found
What KDP Print Previewer errors this preflight helps you catch
KDP often groups cover size, trim size and bleed, and other formatting issues inside Print Previewer. This preflight focuses on the upload-level problems authors hit most often after a cover is rejected.
Match the live book specs
Set the same binding, trim size, paper type, and page count that KDP is using for the current job.
Upload the file you actually sent
Use the current JPG, PNG, or WEBP you exported from Canva, Photoshop, or another workflow.
Read the size, bleed, and spine clues
The checker compares image ratio, likely asset mode, and effective DPI against the expected KDP full-wrap target.
Why KDP says your cover is the wrong size
A KDP cover rejected message usually does not mean you picked the wrong trim size on the calculator. More often, it means the uploaded sheet no longer matches the exact outside dimensions KDP expects after back cover, front cover, spine width, and bleed are all included. KDP groups these under Print Previewer, cover size, trim size and bleed, and general formatting issues, while authors usually search for KDP cover wrong size.
That mismatch often happens after a correct template turns into a wrong export. A designer may start with the right numbers, then upload front-only art, resize the canvas in Canva, or change page count after the spine was calculated. The inputs feel correct, but the delivered file is not the same full-wrap sheet anymore.
Expected cover size is ... what that message really means
When KDP says expected cover size is a specific width and height, it is describing the complete print-ready spread, not only the front cover. The number already includes back cover, front cover, spine width, and bleed. If one of those pieces is missing, cropped, or stretched, KDP sees the whole upload as the wrong size.
This is why page count, paper type, and binding have to stay in sync from design to export. If page count changes, the spine changes. If paper changes, the spine can change too. That is why a file that looked fine yesterday can still trigger a KDP spine width error today.
Quick map of common KDP cover formatting errors
Use this table when KDP cover rejected is vague and you need to decode the real issue fast.
| Message or symptom | What it usually means | What to check next |
|---|---|---|
| KDP cover rejected / KDP cover wrong size | The uploaded sheet does not match the full wrap KDP calculated for the book. | Check trim, page count, export dimensions, and whether you uploaded front-only art. |
| Expected cover size is ... | KDP is telling you the exact outside width and height it wanted for the full spread. | Compare the upload against a fresh calculator or template output before re-exporting. |
| KDP bleed error | Background or artwork stops at the trim edge, or text sits too close to the cut line. | Extend background into bleed and move text inward to the safe area. |
| KDP spine width error | The spine in the upload no longer matches the current page count and paper settings. | Recalculate spine width and rebuild the wrap instead of stretching the old file. |
| KDP Print Previewer errors | KDP detected one or more cover formatting issues during preview. | Use the preview note plus the preflight result to isolate size, bleed, or asset-mode problems. |
Canva KDP cover wrong size: the 4 most common causes
Canva is a common source of KDP cover wrong size problems because resizing feels harmless even when the print sheet has to be exact. These are the four patterns that cause the most rejected uploads.
Front cover exported instead of full wrap
The design only includes the front panel, so KDP never sees the back cover, spine, or bleed it expects.
Custom canvas was rounded or resized by hand
A manual canvas size may be close, but close is not enough when KDP expects an exact outside width and height.
Page count changed after the cover was designed
A new page count changes spine width. Reusing the old spread can cause an immediate KDP spine width error.
Bleed and safe zones were ignored during final edits
Backgrounds that stop at trim or text that sits too close to the cut line often turn into a KDP bleed error in preview.
How to fix KDP bleed error and KDP spine width error before you re-upload
The safest recovery path is to stop guessing at export sizes and rebuild from the current book specs. Use this order so you do not keep chasing one formatting issue after another.
1. Lock the live KDP specs
Confirm trim size, binding, interior paper, and page count in the dashboard before you touch the cover again.
2. Generate the full-wrap target again
Use the calculator, template, or creator to get the current expected cover size with bleed and spine included.
3. Rebuild the bleed and spine areas
Extend background fully to the outside edges and keep text away from trim, hinge, and narrow spine areas.
4. Export high resolution and rerun preflight
Upload the new image here first. If the size check passes and KDP still rejects the file, the remaining blocker is likely PDF-specific.
FAQ about KDP cover formatting errors
Because KDP is checking the outside size of the full spread, not only the trim size you selected. The upload has to include the back cover, front cover, current spine width, and bleed in one exact sheet.
A KDP bleed error usually means the background does not extend far enough past the trim line, or important text and graphics are sitting too close to where the book will be cut.
The most common cause is that page count or paper type changed after the cover was designed. That changes the spine width, so the exported file no longer matches the current book setup.
This preflight is best for KDP cover wrong size issues, expected cover size mismatches, front-only versus full-wrap mistakes, low effective DPI, early KDP bleed error clues, and many KDP spine width error cases.
In Canva, the usual problems are exporting only the front cover, rounding the custom canvas size, or reusing an old spread after page count changed. The inputs can be right while the final export is still wrong.
Not yet. This version focuses on uploaded images and catches the most common visual preflight failures. PDF/X, CMYK, embedded fonts, and other PDF-specific checks still need a later PDF preflight or the creator export flow.
Related resources
KDP Cover Creator
Rebuild the full-wrap sheet with the current trim, bleed, and spine math.
Fix it in CreatorKDP Cover Size Calculator
Check the exact full-cover dimensions before running another export.
Calculate full-wrap sizeKDP Cover Templates
Download the right template if the current canvas was built from the wrong preset.
Pick a template sizeKDP Cover Requirements
Review the official trim, bleed, safe area, and spine rules before the next export.
Read the requirementsKDP Cover Rejection Checklist
Use a step-by-step checklist when KDP Print Previewer errors keep repeating.
Open the checklist