Do you have illustrations meant to fill the available viewing space on a Kindle page? If so, there are a couple of things you need to know:
- The dimensions of the viewable area on the Kindle device. Unlike a book cover, which fills the screen at 600 by 800 pixels, pages have margins on all four sides and a narrow location bar at the bottom, which takes up space. A caption also requires some vertical space.
- The dimensions of an image that will not trigger resizing by Amazon’s DTP (Digital Text Platform) or popular publishing applications, such as MobiPocketCreator or Kindlegen. Resizing reduces image quality. Increasing image size can result in visible pixelation. Reduction also degrades quality, but not as dramatically.
Important! This post applies to older eInk Kindles. Newer Kindles have a variety of screen sizes and resolutions. See Full-Screen Interior eBook Images for updated information prior to release of the HDX devices. See Feed Kindle Fire More Pixels for post-HDX information about maximum image width.
Amazon’s formatting guidelines used to recommend that large images be 450 pixels by 550 pixels, and the DTP Forums will repeat that advice and provide conflicting answers. Images made at 450 by 550 pixels will not fill the viewable area. Images at 600 by 800 pixels are perfect for the cover image, but are bigger than the viewable area. They will be compressed to fit, but zoom nicely when clicked.
The latest Publishing Guidelines state that 500 by 600 pixels is the maximum size. The Formatting Images help page says nothing at all about dimensions, but says: “An HTML image with an aspect ratio of 9 to 11 automatically displays with maximum screen coverage.” It’s enough to make your brain itch!
Dimensions that fill most of the screen and do not trigger resizing are close to, but not exactly, 500 by 600 pixels. A more accurate demonstration of what actually works is shown for Kindle 1 and Kindle 2 devices by Joshua Tallent, in Kindle Formatting: The Complete Guide. I’ve created similar test images for Kindle New Generation, and the results show that his recommendation for Kindle 2 works for Kindle New Generation, as well. However, I think it’s possible to use an image a few pixels larger with an acceptable, and very slight, decrease in quality.
Be aware that on the Kindle Previewer, the optimal dimensions that Tallent advises for Kindle 2 (520px by 622px) are the only ones that displayed perfectly. Images that deviate even a couple of pixels display distortion or banding with test images. Nevertheless, they displayed very well on the Kindle device itself, and look good when clicked to “zoom” in. The discrepancy is surely due to the difference in resolution between a computer screen (96ppi, 120ppi or more) and the Kindle New Generation eReader (167ppi). Kindle for PC is, by necessity, the same resolution as a computer screen. Images will look bigger on a PC than they do on your Kindle device because of the difference in pixel density and you can view them in a window significantly larger than the Kindle reader screen. That’s good! You want a bigger reading area anyway, no?
When creating images for viewing on a PC or device with a screen, the pixel dimensions are what matters, not the resolution. For example, if you make an image 600 x 800 pixels using Photoshop, it will look exactly the same on screen whether you use 72ppi or 300ppi. If you are making images for a book to be printed, resolution affects the print size. Plan ahead and make the print images at 300ppi for CreateSpace first, so you never scale up from small screen images. Scaling up causes pixelation.
I think the best way to get your head around image dimensions and decide what you want to do for your own illustrations is to see test images on your own Kindle, or in Kindle Previewer, if you don’t own a Kindle device. I’ve made a very short Kindle booklet with my test images that you may download (link below). See what you think!
Free Kindle Preview File
[Added: This file was made when the eInk Kindle 3 was the latest thing. It’s now over 3 years old and of little value for testing on current Kindles. It would be more useful for you to create your own little test booklet of images and load it in Kindle Previewer or your own Kindle(s) to see how they look. It takes less time than you think, especially if you use Sigil to create a test ePub to feed to Kindle Previewer, which includes Kindlegen conversion software.]
Download Kindle Maximum Image Size (PRC) (98KB). Save the file to your computer for viewing in Kindle Previewer or Kindle for PC.
To transfer the file to a Kindle device, connect the Kindle to your PC with the USB cable. In Windows, click the Start Button and then Computer. Find the drive letter assigned to the Kindle and expand it to see all the folders. Then drag the downloaded file from your Download folder into the Kindle Documents folder. The plus sign (+) indicates that a copy is being placed in the folder on the Kindle drive. Eject the Kindle. The booklet will be listed on your Home screen.