Etar vs Decsync Calendar Sync
A side-by-side comparison of two self-hosted calendar & contacts options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Etar | Decsync Calendar Sync |
|---|---|---|
| Deploy effort | Read-the-docs project | Read-the-docs project |
| Health score | 87 · Excellent | 15 · At risk |
| Category | Calendar & Contacts | Calendar & Contacts |
| License | GPL-3.0 | GPL-3.0 |
| Language | Java | Kotlin |
| Setup difficulty | Medium | Medium |
| Min. RAM | 256 MB | 128 MB |
| Deployment | source | source, binary |
| GitHub stars | ★ 2,603 | ★ 699 |
| First released | 2016 | 2018 |
| Replaces | Google Calendar | Google Calendar |
What are Etar and Decsync Calendar Sync?
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
Decsync Calendar Sync
Decsync is a method and toolset for synchronizing calendars and contacts via a shared folder rather than a central server. Self-hosters pair it with a file-sync service to keep events consistent across devices.
- Folder-based sync
- No central server
- Calendar and contacts
- Pairs with any file sync
Etar vs Decsync Calendar Sync: key differences
Etar is written in Java, while Decsync Calendar Sync is built with Kotlin. Decsync Calendar Sync is the lighter option, starting around 128 MB of RAM against 256 MB for Etar. Etar is the more established project (first released 2016), while Decsync Calendar Sync arrived in 2018. Etar has the considerably larger community, at 2,603 GitHub stars versus 699.
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 Decsync Calendar Sync if…
- Server-free architecture
- Privacy friendly
Watch out for
- Requires a sync layer
- Setup is non-trivial
Frequently asked questions
Is Etar or Decsync Calendar Sync 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 Decsync Calendar Sync free and open-source?
Yes. Etar is licensed under GPL-3.0 and Decsync Calendar Sync under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Etar and Decsync Calendar Sync with Docker?
Etar: check the project docs for container support. Decsync Calendar Sync: check the project docs for container support.
Which is lighter on resources, Etar or Decsync Calendar Sync?
Decsync Calendar Sync has the smaller minimum footprint at 128 MB of RAM, compared to about 256 MB for Etar. Real-world usage depends on library size, user count, and enabled features.