KOReader and Calibre: wireless books, and syncing highlights back
Two different jobs go under 'KOReader Calibre sync'. One is getting books onto the device over Wi-Fi. The other is pulling your KOReader highlights and progress back into Calibre. Here is how to do each.
Last updated September 2026
People search for “KOReader Calibre sync” meaning one of two things. They are unrelated, so decide which you want.
Job 1: send books to KOReader over Wi-Fi
KOReader has built-in Calibre support — it connects to Calibre’s wireless content server and lets you browse and download your library, no cable.
- In Calibre on your computer: Connect/share, then Start wireless device
connection (or Start Content Server). Note the address it shows, like
192.168.1.50:9090. - In KOReader: the menu, then the plug/tools icon, then Calibre, then Wireless connection. Enter that address, or let KOReader scan for it on the network.
- KOReader now shows your Calibre library. Download individual books, or a whole shelf, straight to the device.
This also works the other way for metadata: KOReader can hand a book’s reading status back to Calibre’s wireless connection while connected.
An alternative that needs no server running is an OPDS catalogue — Calibre’s content server exposes one, and KOReader can add it under OPDS in the same menu. Same result, browse-and-download, and it works from anywhere you can reach the server.
Job 2: get KOReader highlights and progress into Calibre
KOReader stores your highlights, bookmarks and progress in a sidecar file
next to each book (a .sdr folder). To surface that in Calibre you need a
third-party Calibre plugin — search Calibre’s plugin index for the
“KOReader” plugin. Once installed:
- Connect the device by USB. The plugin reads the
.sdrsidecars and writes the highlights, the reading percentage and the last-read date into custom columns in your Calibre library. - It is one-directional — device to Calibre — and it is a snapshot each time you run it, not a live sync.
- It is unofficial and maintained by a volunteer, so it can lag behind a KOReader format change.
This is the route if you want your highlights searchable in Calibre or exported from there. It does nothing for getting books onto the device — that is Job 1.
The short version
To load books wirelessly: Calibre’s wireless device connection or its OPDS catalogue, added in KOReader’s Calibre menu. To collect your highlights in Calibre: the third-party KOReader plugin for Calibre, run over USB.