The file-size limit for delivery to Kindle is 24MB. For tips on reducing file size, please see the optimization guidelines here.
A note on ePubs: NetGalley uses Amazon’s KindleGen software to convert EPUB files to MOBI files. The KindleGen conversion process duplicates the information within the original EPUB file, which causes the MOBI file to be larger than the original EPUB file. We’ve found that the difference in size varies from file to file. As a rough estimate however, we assume that file sizes are likely to double. If an EPUB file is 2MB, the resulting MOBI file is likely to be approximately 4MB.
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:
- Disable the Kindle option.
- Upload a smaller EPUB file (reducing the EPUB file size is most easily done by reducing the size of images within the file).
- Create a native MOBI file and uploading that file to NetGalley. (This approach may allow you to reduce the overall file size without reducing the image sizes.)