What is sideloading?
Updated:
Sideloading means putting an e-book on a reader yourself, by USB cable, email or an app, instead of buying it in the device's store. Converted EPUBs always reach a reader this way.
Why it matters when you convert a PDF to EPUB
How you sideload depends on the device: a Kobo or PocketBook takes the EPUB by USB, while a Kindle takes it through Amazon's Send to Kindle, which converts it for the device. Sideloaded books work offline like store books but do not sync reading positions across devices on every platform.
Related terms
Convert a PDF to EPUB
Convert up to 5 pages free, no account needed.