NetGalley uses Amazon’s KindleGen software to convert EPUB files to MOBI files. This conversion process will impact file size. We’ve found that the difference in size varies from file to file but, in general, file sizes are likely to double. If an EPUB file is 2MB, the resulting MOBI file is likely to be approximately 4MB.
The file-size limit for delivery to Kindle is 24MB. If you find that a MOBI file created on NetGalley (using the KindleGen EPUB-to-MOBI conversion) is too large to deliver to Kindle, there are a few ways to address the issue:
- Upload a smaller EPUB file (reducing the EPUB file size is most easily done by reducing the size of images within the file). For tips on reducing file size, please see the optimization guidelines here.
- Create a native MOBI file and upload that file to NetGalley. This approach may allow you to reduce the overall file size without reducing the image sizes.
- Disable the Kindle option. NetGalley members will not see the option to download your book to their Kindle devices.
In some cases, this conversion process can result in formatting changes. We recommend testing the converted file using a NetGalley reader account to ensure that the file is delivered and looks as expected.