Best Image Format for E-Book Covers
JPG is the best format for e-book covers across all major platforms including Amazon Kindle, Apple Books, Kobo, and Barnes & Noble Nook. Every major e-book distribution platform specifies JPG as the accepted or preferred format for cover images. PNG is accepted by some platforms but often results in larger files that may be rejected or converted to JPG during processing.
Your e-book cover is the primary sales tool for your book. In online bookstores, readers browse thumbnail-sized cover images and make split-second purchase decisions based on the cover's visual appeal. The cover must look compelling at both thumbnail size (roughly 150 pixels tall in search results) and full-size display on the product page.
Here is how to prepare e-book covers that meet every platform's requirements and look great at every display size.
Platform-Specific Requirements
Each e-book platform has specific cover image requirements. Meeting the most demanding specifications ensures your cover works everywhere.
- Amazon Kindle (KDP): JPG or TIFF. Minimum 625x1000 pixels, ideal 2560x1600 pixels. Maximum 50MB. Height-to-width ratio of 1.6:1.
- Apple Books: JPG or PNG. Minimum 1400 pixels on the shortest side. Recommended 1600x2400 or higher.
- Kobo: JPG or PNG. Minimum 1400x1873 pixels. Recommended 1600x2400.
- Barnes & Noble (Nook Press): JPG. Minimum 750x1200 pixels. Recommended 1400x2100 or higher.
- Google Play Books: JPG or PNG. Minimum 640x1024 pixels. No maximum specified.
- Universal safe specification: JPG at 2560x1600 pixels satisfies all platforms.
Why JPG Over PNG for E-Book Covers
E-book covers are embedded in the EPUB or MOBI file that readers download. A PNG cover at 2560x1600 can be 5-15MB, while the equivalent JPG at quality 90 is 300-800KB. Since the cover is bundled with the e-book file, larger cover images increase the total download size.
More importantly, e-reader devices (Kindle Paperwhite, Kobo Clara, etc.) have limited processing power and memory. A JPG cover loads faster on these devices. Amazon KDP specifically recommends JPG for optimal performance on Kindle devices.
Optimal Quality Settings
Since e-book covers are displayed on screens (not printed), you have more flexibility with quality settings than print media. However, the cover needs to look sharp at both full size and thumbnail size.
- JPG quality: 90-95. This balances file size with quality. Below 85, compression artifacts become visible, especially around text.
- Color space: sRGB. E-readers and bookstore websites use sRGB. CMYK covers will display with incorrect colors.
- Resolution: 72-150 DPI is standard for screen display. The pixel dimensions matter more than DPI.
- Recommended dimensions: 2560x1600 pixels for Amazon KDP. 1600x2400 for everything else.
- File size: keep under 2MB for fastest loading. Under 50MB for Amazon's hard limit.
Designing for Thumbnail Visibility
In bookstore search results and recommendation carousels, your cover appears as a thumbnail roughly 150-200 pixels tall. The design must be compelling and readable at this tiny size.
Test your cover at thumbnail size before finalizing. If the title is unreadable or the imagery is unclear at 150 pixels tall, simplify the design.
- Use large, bold title text that reads at 150px thumbnail size.
- Limit the title to 4-5 words maximum for readability.
- High contrast between text and background is essential.
- Simple compositions with a single focal point outperform complex designs.
- Author name can be smaller but should still be visible at thumbnail size.
- Genre conventions matter: readers expect certain color palettes and imagery for each genre.
Print-on-Demand vs E-Book Only
If you are publishing both an e-book and a print edition (via KDP Print, IngramSpark, etc.), you need two different cover files. The print cover is typically a single PDF or TIFF file that includes the front cover, spine, and back cover as one image, with bleed and crop marks.
Your e-book cover JPG is just the front cover. Do not use the full print cover wrap for the e-book version. Export the front panel separately at the required e-book dimensions.
Frequently Asked Questions
What size should a Kindle e-book cover be?
Amazon KDP recommends 2560x1600 pixels (height-to-width ratio of 1.6:1) in JPG format. The minimum is 625x1000 pixels, but using the recommended size ensures the cover looks sharp on all Kindle devices including tablets.
Should e-book covers be JPG or PNG?
JPG is the recommended format for e-book covers. All major platforms accept JPG, it produces smaller file sizes that load faster on e-readers, and Amazon KDP specifically recommends JPG for optimal Kindle performance.
What DPI should an e-book cover be?
DPI is less important than pixel dimensions for e-book covers since they display on screens, not in print. Use 72-150 DPI at the platform's recommended pixel dimensions (2560x1600 for Amazon KDP). The pixel count determines actual display quality.
Can I use the same cover for e-book and print?
The same front cover design can be used, but the files are different. The e-book cover is a JPG of just the front panel. The print cover is a full wrap (front, spine, back) as a PDF or TIFF with bleed and trim marks. Export each version separately.
Convert PNG to JPG for e-books