We often get asked what an eBook filesize should be. It varies from retailer to retailer, but if you want to use one source ePUB file to all the retailers you need to keep it under 20MB. We’ve created a chart for you below.
|Barnes & Noble
*Note: As per Ben Dugas of Kobo they don’t automatically fail files that are larger than 200 MB but they are more likely to have performance issues or not load.