Check four questions: can the book be transferred, can it be opened, can reading position move, and can annotations move? A yes to the first question does not answer the other three.
Start at the source
A DRM-free publisher download is different from a protected store purchase or a time-limited loan. Identify the source before choosing a device or conversion workflow. A filename extension alone does not describe the access rights.
Check the reader, not just the hardware
An Android eReader can run different reading apps, each with its own library and state. Record the specific app and account alongside the device. A browser and a native reader may not use the same position identifiers.
Verify with one book
Use a known file and test a chapter, a note, and an offline session. Record the outcome for your exact combination. Re-test after changing reader software or replacing the book with a new edition.
The details, at a glance.
| Consider | What to look for |
|---|---|
| DRM-free EPUB → Kobo | File reading is a format question; shared state needs a compatible sync route |
| Calibre → BookFusion | Documented plugin route; library sync is one-way from Calibre |
| Libby → eReader | Availability depends on the lending route and device |
| OPDS → reading app | Catalog discovery and downloads; no implied position sync |
A few things worth asking.
Does this directory certify devices?
No. It explains documented routes and the tests to run; firmware and app changes can affect results.
Can converting a file make every feature work?
Conversion may change the format, but does not establish shared accounts, annotation compatibility, or lending access.
Go to the source
Documentation consulted for the routes and terminology on this page. Product behavior can change; verify your exact setup.
BookFusion: Calibre plugin and sync direction Libby: transferring loans to an eReader OPDS specificationsWritten by Binge Reader. Our comparisons explain documented workflows and practical tradeoffs; they are not independent product benchmarks.