What you need to do

Calibre is a desktop library manager for ebooks. KOReader is a reading app that runs on e-ink devices like Kindle, Kobo, and PocketBook. To read books from Calibre on your device through KOReader, you connect them by pointing KOReader to the folder where Calibre stores your library files.

The connection happens on your device itself, not in Calibre. You tell KOReader where to find your books, and it reads them from there. This means your device needs access to the folder — either because the books are on the device's storage, or because the device can see a network folder on your computer.

Key Takeaways

  • KOReader reads books directly from your Calibre library folder without needing Calibre itself to be running.
  • You can store the Calibre folder on your device's storage, on a memory card, or on a network location your device can reach.
  • The connection is made in KOReader's file browser by pointing it to the folder path where Calibre keeps your books.
  • If you use a network folder, your device must support network access and you will need the correct network address for your computer.

Moving your Calibre library to your device

The simplest setup is to copy your Calibre library folder directly onto your device or its memory card. Open Calibre on your computer and look in the top menu for Preferences (or Settings on some systems). Find the section labeled "Library" or "Calibre Library Location" — it will show you the exact folder path where your books are stored.

Copy that entire folder to your device using a USB cable or file manager. The folder name usually starts with "Calibre Library" or is simply called "calibre". Once it is on your device, you know the exact path — for example, /mnt/sdcard/Calibre Library on an Android-based device, or /mnt/onboard/Calibre Library on a Kobo.

This method works well if you have enough storage space and do not need to sync changes between your computer and device. If you add books to Calibre later, you will need to copy the updated folder again.

Pointing KOReader to the library folder

Open KOReader on your device and go to the file browser. Look for a menu option called "Go to folder", "Add folder", or "Bookshelf" — the exact name varies by KOReader version. Tap or select the option to enter a custom folder path.

Type the full path to your Calibre library folder. If you copied it to your device, use the path where you put it. If the folder is on a network location, use the network path — for example, smb://192.168.1.100/Calibre Library for a Windows share, or nfs://192.168.1.100/home/user/Calibre Library for an NFS share.

Press Enter or confirm. KOReader will scan the folder and display all the books it finds. You can now open any book directly from KOReader without copying individual files.

Using a network folder instead of copying files

If you want to keep your library on your computer and access it wirelessly, set up a network share. On Windows, right-click your Calibre library folder, select Properties, go to the Sharing tab, and enable sharing. On Mac or Linux, use System Preferences or your file manager to share the folder over SMB or NFS.

Your device must support network access. Most modern e-readers with KOReader can connect to SMB shares (Windows file sharing) or NFS shares (Unix-style sharing). Check your device's network settings to confirm it can see your home network.

Once the share is active, use the network path in KOReader as described above. The advantage is that you do not need to copy files — KOReader reads them directly from your computer. The disadvantage is that your device must be on the same network and the connection may be slower than reading from local storage.

Organizing books within the Calibre folder structure

Calibre organizes books into subfolders by author and title. When you point KOReader to the Calibre library folder, it will show this same folder structure. You navigate through author folders to find individual books.

If you prefer a flat list instead, some versions of KOReader have a setting to flatten the folder view or to show all books in a single list regardless of subfolder. Check KOReader's preferences under "File browser" or "Display" to see if this option is available on your version.

Alternatively, you can tell Calibre to organize books differently. In Calibre's Preferences, under "Library", you can change the folder structure pattern — for example, to sort by genre instead of author, or to use a flat structure with all books in one folder. Any changes you make in Calibre will be reflected the next time KOReader scans the folder.

Troubleshooting connection problems

If KOReader cannot find the folder, double-check the path. Paths are case-sensitive on Linux and Mac but not on Windows. Make sure you have typed the path exactly as it appears in your file manager, including all slashes and folder names.

If you are using a network path and KOReader cannot connect, verify that your device is on the same network as your computer and that the network share is actually turned on. Try pinging your computer's IP address from your device to confirm the connection works. If the share requires a username and password, some network protocols (like SMB) will prompt you for credentials when you first connect.

If KOReader shows the folder but no books appear, check that the Calibre folder actually contains book files. Calibre stores books in subfolders named after authors — look inside one of those folders to confirm there are .epub, .pdf, .mobi, or other book files present. If the folder is empty, your Calibre library may not have been copied correctly.

Syncing changes between Calibre and KOReader

KOReader reads books from your Calibre folder but does not write back to it. If you add new books to Calibre on your computer, KOReader will not see them automatically unless you refresh the folder view or restart KOReader.

If you are using a network folder, simply refresh KOReader's file browser to see new books. If you copied the folder to your device, you will need to copy the updated Calibre folder again to see new additions. This is why a network setup is more convenient if you add books frequently.

Bookmarks and reading progress you make in KOReader are stored separately and do not sync back to Calibre. Each app keeps its own records of where you are in a book.

Frequently Asked Questions

Do I need Calibre running on my computer for KOReader to read the books?

No. KOReader reads the book files directly from the folder. Calibre only needs to be running if you are adding new books or making changes to your library. Once the books are in the folder, KOReader can access them anytime.

Can I use both Calibre and KOReader to read the same book at the same time?

Yes, but they will not share your reading progress. If you read to page 50 in Calibre, KOReader will still show the book as starting from the beginning. Each app tracks your position separately.

What book formats does KOReader read from a Calibre folder?

KOReader supports EPUB, PDF, MOBI, AZW, TXT, HTML, and several other formats. Calibre can convert books to any of these formats if needed. Check KOReader's documentation for your specific device to see the full list of supported formats.

Is it safe to edit my Calibre library while KOReader is reading from it?

It is generally safe, but avoid deleting or moving files while KOReader has a book open. If you add new books or rename folders in Calibre, refresh KOReader's file browser to see the changes. Closing and reopening KOReader will also refresh the view.

Can I connect multiple devices to the same Calibre library?

Yes. Each device can point to the same network folder or have a copy of the same Calibre library folder. If you use a network folder, all devices will see the same books and any updates you make in Calibre. If you copy the folder to each device, you will need to update each copy separately when you add new books.