The KDP file size limit depends on the file. On KDP’s help pages an ebook cover must be less than 50 MB, a paperback cover should be 40 MB or less (650 MB will not convert), and a print manuscript can be up to 650 MB. The ebook manuscript page states no size limit. Here is each cap with its source, and the Smol setting for it.
| What you are uploading | The limit you hit | The Smol setting |
|---|---|---|
| Ebook cover (JPEG or TIFF) | Under 50 MB; ideal 2,560 × 1,600 px; 1000 × 625 px minimum | Compress, output JPG, quality 90, maximum dimension 2560 (not the 2000 default) |
| Images going into the ebook | No stated manuscript cap, but delivery cost is charged per megabyte | Compress, JPG, quality 75 to 80, maximum dimension about 1600 |
| Paperback cover PDF | 40 MB or less recommended; 650 MB will not convert | Compress the art you place in it at quality 90, then export the PDF from your layout tool |
| Print interior PDF | 650 MB; images at least 300 DPI | Compress images before you place them; avoid PDF presets here (see below) |
What are the KDP file size limits for each file?
KDP publishes a different number for each file type, and the ebook manuscript has none. The figures below come from Amazon’s own help pages; check them again before a launch, because KDP edits them.
| File | What the page says | Source |
|---|---|---|
| Ebook cover | Less than 50 MB | KDP cover specs |
| Ebook manuscript | No file-size limit stated; accepts DOC/DOCX, KPF, EPUB, HTML (zip), RTF, TXT, and PDF in some languages | KDP ebook formats |
| Paperback cover | Files over 650 MB will not convert; 40 MB or less recommended | KDP paperback cover |
| Print manuscript | Not more than 650 MB; images at least 300 DPI | KDP print manuscript |
| Ebook delivery cost | Charged per megabyte of the file; US $0.15/MB at Amazon.com (70% option) | KDP pricing |
The cover figure and the print figure are caps. The delivery cost is different: it is a cost, not a cap, and it is the reason a smaller ebook earns more.
What is the right Kindle cover size in pixels?
Make the cover 2,560 pixels tall by 1,600 wide. KDP calls that ideal, sets a minimum of 1000 by 625, and says not to exceed 10,000 in either direction. It asks for 300 PPI, JPEG or TIFF, in RGB.
A 2,560 × 1,600 JPEG is far below the 50 MB cap at any sensible quality, so the cap rarely decides anything. What decides your upload is the pixel size and the format. From quality 90 Smol uses 4:4:4 chroma, which keeps fine colored text edges on a title cleaner than the 4:2:0 used at quality 75 and below. These quality numbers are our starting points, not KDP rules. Check the result at full size, especially the title.
How do I do ebook image compression without wrecking the art?
Compress the images before you place them in your word processor or formatting tool, not after. KDP’s delivery charge counts the megabytes of the finished ebook, and images are almost always most of them.
The arithmetic is simple. At US $0.15 per MB on the 70% option, a 10 MB ebook costs $1.50 per sale in delivery and a 2 MB one costs $0.30. The $1.20 difference comes out of your royalty on each sale. The rate is Amazon.com’s; other stores list their own.
| Image | Operation | Setting |
|---|---|---|
| Ebook cover | Compress, output JPG | Quality 90, maximum dimension 2560 |
| Photos or color illustrations inside an ebook | Compress, output JPG | Quality 75 to 80, maximum dimension about 1600 |
| Line art, maps, diagrams with flat color | Compress, output PNG | Quality 75, then look for banding |
| Print interior images | Compress, original format | Raise or switch off resize; keep pixels for 300 DPI at trim size |
| HEIC photos from a phone | Compress, output JPG | Use Compress, not Convert, so quality applies |
Smol’s image defaults strip metadata, including copyright and contact fields. For reader files that is usually fine; switch it off if you want your credit line to travel with the art. In our benchmark, at default settings Smol made 24 high-quality JPEG photos 69.3% smaller. Those were small 768 × 512 film photographs, so your own files will differ.
How do I shrink the images in a book folder on a Mac?
Copy your art folder, drop it into Smol, set the format and size, and read the largest output. Smol writes copies with a _compressed suffix and, by default, never overwrites the originals.
Copy the folder of art
Keep your layered files and full-size masters where they are. Compress copies.
Drag the folder into Smol
Photos, maps and a cover can go in one batch.
Set output and maximum dimension
Use the table above. Interior ebook art: JPG, quality 75 to 80, about 1600. Cover: JPG, quality 90, 2560.
Compress and check
Open the largest output and the cover at full size. Smol sets quality and pixels, not output bytes, so confirm the size yourself.
Place the compressed copies in your book
Insert them into your manuscript or formatting tool and export. Check the finished file size before uploading.
My manuscript file is too large for KDP. What do I do?
Find out which file is large. For an ebook, KDP’s manuscript page states no size cap, so the usual fix is smaller images and a lower delivery cost. For print, the cap is 650 MB.
- Embedded images dominate nearly every oversized manuscript. Compress them first, using the table above.
- For a print PDF, KDP asks for images of at least 300 DPI and suggests a maximum of 600. Anything above that is bytes you do not need.
- Embed fonts and keep the interior one file. KDP asks you to embed fonts, which Smol does not do for you.
Why PDF presets are the wrong tool for a print interior
Smol’s PDF presets cap the long edge in pixels: 600, 900, 1200, 1800 and 2400 for Tiny, Small, Medium, Large and Original. On a 9-inch page, Original works out to about 267 PPI and Large to 200, below KDP’s 300 DPI. A 5.5 × 8.5 inch trim gets 282 PPI at Original, and an 8.5 × 11 inch page 218. Original also re-encodes; it is not lossless. For print, compress the images yourself and keep the PDF export from your layout tool. See compressing a PDF for print without losing 300 PPI and what the presets do.
What are the IngramSpark file requirements, and do they match KDP?
Not necessarily. IngramSpark publishes its own file creation guide. Read its current specs rather than reusing KDP’s numbers before you export a file for both.
The Smol side does not change: resize the images to the pixel size your trim needs, set quality, and check the output. If you publish wide, keep one master and make a copy per retailer, since Smol’s default output name is the same for every run and several sizes need separate runs and renaming. Illustrators can also see the illustrator guide and print-on-demand sellers the upscaling guide.
What do authors use today to shrink images?
Free tools come first. Preview and the sips command are built into every Mac, and ImageOptim is free. Each solves part of the job.
| Tool | Cost | Fits when | Falls short when |
|---|---|---|---|
| Preview export | Built in | A few images, one at a time | A whole folder of art |
sips (guide) | Built in | You are comfortable in Terminal and want a fast resize | You want a quality dial and metadata handling in a window |
| ImageOptim | Free | You want lossless; its default saved 8.9% on the same small JPEGs | You want bigger savings than its default lossless mode gives |
| Smol | $29 once | You want a batch with a quality and size setting in one window | You need lossless output or a build-server tool |
For a wider comparison, see our every method compared guide and the ImageOptim comparison.
When Smol is the wrong tool
Smol will not fix every file problem an author hits. Skip it in these cases.
- You need lossless images. Smol always re-encodes images; ImageOptim is the lossless route.
- You need to build the book. Smol does not format an EPUB, edit a PDF, merge or split pages, or embed fonts.
- You need a PDF at a fixed DPI. Its presets are pixel caps, so DPI depends on page size.
- You need a guaranteed byte count. Smol sets quality and pixels; you check the output against the cap.
- You are on Windows. Smol is macOS only.
Frequently asked questions
What is the KDP file size limit for an ebook cover?
KDP’s cover page says the cover image must be less than 50 MB. It asks for 2,560 pixels tall by 1,600 wide as the ideal, 1000 by 625 as the minimum, nothing above 10,000 in either direction, 300 PPI, and JPEG or TIFF in RGB. Check the page again before you upload, since Amazon edits it.
What is the KDP file size limit for a manuscript?
For an ebook manuscript, KDP’s formats page states no file-size limit. For a print manuscript, KDP’s page says not more than 650 MB. Separately, KDP charges ebook delivery per megabyte on the 70% option, US $0.15 per MB at Amazon.com, so a smaller ebook keeps more of each sale.
What is the right Kindle cover size?
KDP calls 2,560 pixels tall by 1,600 wide ideal, with a minimum of 1000 by 625 and a maximum of 10,000 in either direction. In Smol, set the maximum dimension to 2560, because the default fits images inside 2000 by 2000 pixels. Open the result at full size to check the title text.
How do I shrink images for an ebook without ruining them?
Compress the images before you place them in your formatting tool. In Smol, choose Compress, output JPG, quality 75 to 80, and a maximum dimension of about 1600 pixels for interior art, then compare the result against the original. These are starting points, not KDP rules, so look at fine detail before you commit.
What are the IngramSpark file requirements?
IngramSpark publishes them in its own file creation guide, and you should not assume they match KDP’s. Read its current guide before exporting a file for both retailers. A practical approach is to keep one full-size master of each image and make a compressed copy per retailer, then check each output against that retailer’s limits.
My manuscript file is too large for KDP. Will Smol fix it?
If the size comes from images, yes, compress them before you place them. If it comes from missing embedded fonts, a layout export or structure, no, because Smol does not edit PDFs or format EPUBs. For print, avoid the PDF presets, since their pixel caps can fall below 300 DPI on a 9-inch page.
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