

With the help of iCloud Drive, you can easily sync iBooks PDF among your iOS devices. Then you can open iBooks app and check all your PDF files with ease. Turn on another iOS device and ensure the iBooks is synced. Turn on iCloud Drive and make sure "iBooks" option is enabled. Tap your iCloud account and enter iCloud interface. Unlock your iPhone or iPad and open "Settings" app. Then you can access PDF files in iBooks app. First, you need to enable iBooks sync feature on iPhone or iPad. ICloud Drive makes it quite convenient to sync various PDF files through iBooks across your all iOS devices with the same Apple account. How to Sync PDF from iBooks to iPhone with iCloud Drive

But I notice that some PDF files and collections in iBooks app do not actually syncing. "Is there any simple way to sync PDF files in iBooks to iCloud Drive? I want to check PDF files on another iPad which using the same apple ID. Is it possible outside of emailing each PDF file to myself and then opening them in PDF Expert to then store on the iCloud Drive?" "I want to move my PDF files from iBooks to the iCloud drive so that they could be accessed from other apps like "PDF Expert" and on any iOS devices.
