EteSync is a secure, end-to-end encrypted calendar and contacts synchronization service. Built as Etebase (EteSync 2.0), it encrypts all data on your devices before it ever reaches the server, so even the server operators cannot read your calendars, contacts or tasks. You can self-host the Python/Django server on your own hardware or use the hosted EteSync service, then sync across Android, iOS, desktop and web clients over standard protocols.

Key Features

• End-to-end encryption — All data is encrypted client-side before upload, so the server never sees plaintext calendar or contact data.
• CalDAV & CardDAV compatibility — An included bridge (etesync-dav) exposes calendars and contacts to standard CalDAV/CardDAV clients such as Thunderbird and Apple Contacts.
• Self-hostable — The Etebase server runs on Python/Django and can be deployed on your own VPS or Docker host.
• Multi-platform sync — Native apps for Android and iOS plus web and desktop clients keep all your devices in sync.
• Tasks support — Synchronize to-do lists as well as calendars and address books, including via the OpenTasks protocol.
• Zero-knowledge design — With end-to-end encryption, a compromised or curious server cannot expose your data.

Why Use EteSync?

EteSync is for people who want the convenience of cloud calendar and contact sync without surrendering privacy. Because everything is encrypted locally before transmission, you get Google-style multi-device synchronisation from a provider that cannot read your data — or from your own self-hosted server for full control.

Use Cases

• Replacing Google or iCloud calendar sync with a privacy-preserving, encrypted alternative.
• Self-hosting an end-to-end encrypted sync server for a family or team that uses CalDAV/CardDAV clients.
• Keeping calendar, contact and task data in sync across Android, iOS, desktop and the web without third-party data exposure.

Platform

Linux · BSD · macOS · Windows · Android · iOS · Docker

Licence

AGPL-3.0 (server) / GPL-3.0 (DAV bridge)

Website

etesync.com