Mark files "offline" in OneDrive for iOS to read them anytime, even when you aren't connected to the Internet. Online edits made to the files sync the next time your iPad, iPhone or iPod Touch connects to the Web, so you get the latest version of the file.
Note: Files marked offline are read-only - you can edit the file only when you're online. If you edit the file offline, it saves as a new file, and does not change the original OneDrive file.
In the OneDrive app, select the files that you want available for offline reading, then on the bottom bar, tap Keep offline .
Note: Only files can be marked for offline reading, not folders.
Files marked for offline reading have the Keep offline icon in the List view. Tap the file listing anytime to open the file for reading.
Once you mark a file offline, OneDrive also lists it in an Offline view. On the bottom navigation bar, tap Offline to instantly find all your offline files.
To stop keeping a file offline, select the offline file, then on the bottom bar, tap Online only .