Why Devices Are Tracked
Books protected by digital rights management are licensed to a reader, not to an unlimited number of machines. Each device that opens a protected book registers itself against your account.
What You Can See
Open Profile → Security, or the My Devices page, for a list of registered machines. Each entry shows the browser and operating system, when it was registered, when it was last used, and lets you remove it.
The Limit
Only devices that actually open protected content count toward your quota, and a device that has not been used recently is released automatically. If you reach the limit you will see a device-limit message when opening a protected book.
Freeing a Slot
- Open the device list.
- Find a machine you no longer use — an old phone, a shared laptop.
- Remove it, then reopen the book on the device you want to use.
If You Keep Hitting the Limit
- Check whether you have browser profiles or devices you forgot about.
- Clearing cookies, using private browsing, or switching browsers registers as a new device.
- Never share your account: each person reading needs their own.
- If the count still looks wrong, contact support through the Help Center.
Offline Copies
A downloaded book occupies a device slot and may carry an expiry date set by its publisher. Reopen it online before it lapses.