Free KoSync Server
Sync your reading progress across all your e-readers
KoSync.eu synchronizes your reading progress, bookmarks, and page positions across Kobo, Kindle, PocketBook, and Android — free, open-source, and hosted in Europe.
Get Started — It's FreeWhy Use KoSync.eu as Your KoSync Server?
Automatic Reading Progress Sync
Your reading position, page percentage, and progress are synced automatically every time you open or close a book in KOReader. No manual steps needed.
Privacy-Focused, Hosted in Europe
No tracking, no ads, no data sharing. Your reading data stays on servers in Europe and is never sold, analyzed, or shared with third parties. GDPR compliant.
Multi-Device E-Reader Support
Switch between Kobo, Kindle, PocketBook, Onyx Boox, or any Android device running KOReader and pick up right where you left off.
How to Set Up KoSync
Create a Free Account
Register with just a username and password — no email required. Optionally add an email address to enable password recovery.
Configure KoSync
In KOReader, open Progress sync settings and set the custom server to https://kosync.eu. Enter your username and password.
Read and Sync Automatically
Your reading progress syncs in the background. Open the same book on another device and continue exactly where you stopped reading.
Supported E-Readers and Devices
Kobo
Clara, Libra, Sage, Elipsa
Kindle
Paperwhite, Oasis, Basic
PocketBook
Touch, InkPad, Era
Onyx Boox
Note, Tab, Poke
Android
Phones & Tablets
Any device that runs KOReader is compatible with KoSync.eu — including Linux desktops and laptops.
What Is KOReader?
KOReader is a free, open-source document viewer optimized for e-ink devices. It supports a wide range of ebook formats including EPUB, PDF, DJVU, CBZ, FB2, MOBI, and many more.
KOReader includes a built-in progress sync plugin that lets you synchronize your reading position across multiple devices. By default it connects to the official KOReader server, but you can point it to any compatible server — like KoSync.eu.
KoSync.eu is a fully compatible alternative that runs independently on European servers, giving you more control over your data and better latency if you're located in Europe.
Features
Full KoSync Protocol
Drop-in replacement for the official sync server — no KOReader modifications needed.
Web Dashboard
Manage your synced documents and connected devices from any web browser.
Password Recovery
Optional email-based password reset if you ever forget your credentials.
No Registration Email Required
Sign up with just a username and password. Your privacy matters.
Account Self-Service
Delete your account and all data at any time from the user dashboard.
Open Source
Fully open-source. Inspect the code, self-host your own instance, or contribute.
Frequently Asked Questions About KoSync
What is KOReader?
KOReader is a free, open-source document viewer for e-ink devices. It supports EPUB, PDF, DJVU, CBZ, FB2, MOBI, and many other ebook formats. It runs on Kobo, Kindle, PocketBook, Onyx Boox, Android, and Linux devices.
Is KoSync.eu free to use?
Yes, completely free. KoSync.eu is a community service. There are no premium tiers, no ads, and no hidden costs. It will remain free.
What data does KoSync.eu store?
Only what is needed for sync: your username, a hashed password, reading progress per document, and device identifiers. If you choose to add an email address, it is stored solely for password recovery. No book content, reading habits, or personal data beyond sync metadata is ever stored.
How is KoSync.eu different from the official KoSync server?
KoSync.eu is an independent, self-hosted instance running on servers in Europe. It is fully compatible with the KoSync protocol and additionally offers a web dashboard to manage your synced documents, devices, and account settings.
How do I configure KOReader to use KoSync.eu?
In KOReader, go to the Progress sync plugin settings. Tap on the server address and change it to https://kosync.eu. Then enter your KoSync.eu username and password. Sync will start automatically.
What if I forget my password?
If you have added an email address to your account, you can reset your password via the login page. Without an email, password recovery is not available — so we recommend adding one in your account settings.
Can I delete my account?
Yes. After signing in, you can delete your account and all associated sync data from the user dashboard at any time. Deletion is immediate and permanent.
Start Syncing Your E-Reader Today
Create your free account and start syncing your reading progress across all your devices in under a minute.
Get Started — It's Free