Etar vs EteSync
A side-by-side comparison of two self-hosted calendar & contacts options — licensing, setup difficulty, resource needs, and what each one replaces.
EteSync
End-to-end encrypted sync for contacts and calendars
| Feature | Etar | EteSync |
|---|---|---|
| Deploy effort | Read-the-docs project | Under-an-hour setup |
| Health score | 87 · Excellent | 20 · At risk |
| Category | Calendar & Contacts | Calendar & Contacts |
| License | GPL-3.0 | AGPL-3.0 |
| Language | Java | Python |
| Setup difficulty | Medium | Medium |
| Min. RAM | 256 MB | 256 MB |
| Deployment | source | docker, bare-metal |
| GitHub stars | ★ 2,603 | ★ 1,770 |
| First released | 2016 | 2017 |
| Replaces | Google Calendar | Google Calendar, iCloud |
What are Etar and EteSync?
Etar
Etar is an open-source Android calendar app forked from AOSP Calendar. It has no server of its own: pair it with DAVx5 and any self-hosted CalDAV server such as Radicale, Baikal or Nextcloud to keep events under your control.
- CalDAV support
- Event API
- Mobile sync friendly
- Open data formats
EteSync
EteSync is a secure, end-to-end encrypted, and journaled solution for syncing contacts, calendars, and tasks. Data is encrypted on the client so the server never sees plaintext.
- End-to-end encryption
- Journaled change history
- Android and iOS apps
Etar vs EteSync: key differences
Etar is written in Java, while EteSync is built with Python. Licensing differs — GPL-3.0 for Etar versus AGPL-3.0 for EteSync. EteSync lists first-class Docker deployment; Etar does not.
Why pick each one
Choose Etar if…
- Open ecosystem
- No vendor lock-in
Watch out for
- Mainly a client project
- Server piece is minimal
Choose EteSync if…
- Released under the AGPL-3.0 license
- First-class Docker support for quick deployment
- Active community (1.8k GitHub stars)
- Written in Python
Frequently asked questions
Is Etar or EteSync better?
Neither is universally better. Etar has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Etar and EteSync free and open-source?
Yes. Etar is licensed under GPL-3.0 and EteSync under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Etar and EteSync with Docker?
Etar: check the project docs for container support. EteSync: yes.