If you decide to self-host EteSync you won’t have to pay for the subscription. Tutorial here.
Reviewed by Gabriel Bachmann
EteSync
etesync.com 2 ratings so far*
Rate EteSync: No account needed
Threat level
Hardened
A hardened pick. Worth the effort once you have chosen to shrink your footprint on purpose. Enough for most people. Threat levels
Our take
The self-hosting escape hatch is the real draw: run your own server and you skip the subscription entirely while keeping end-to-end encrypted, standards-friendly sync for calendars and contacts. The flip side is that development has gone quiet, so weigh that before committing your data to it. Good fit for technical users who want to own the server and value CalDAV-style compatibility. Less ideal if you want a hands-off hosted service with active development.
GitHub at a glance
etesync/server AGPL-3.0 djangoencryptionend-to-end-encryptionetesyncsynchronization
Stars
1,777
+0 this week
Forks
104
28 watching
Last commit
2.3y ago
slowing
Star history
Issues
56% closed
61
open
78
closed
+1 / -0
opened / closed, last 4 weeks
Opened vs closed, last 12 weeks
Commits, last 26 weeks
0 commits, active 0 of 26 weeks
24 contributors since Nov 2017
Languages
- Python 98.7%
- Dockerfile 0.8%
- Shell 0.4%
Updated daily from the GitHub API. Star tracking since Jun 10, 2026.
Website at a glance
etesync.com
A- score 85
Strong website security headers
Graded by Mozilla HTTP Observatory, tested 3d ago
Inspect this site yourself
Measures the security configuration of the tool's own website, not the privacy of the product itself. A strong tool can still score low here.
EteSync alternatives
PrivacyNotes Encrypted notes, tasks, calendar, files, passwords and a journal with mood and medication tracking, all unlocked by one 12-word recovery phrase. Sign up with no email and no password. Open source.
Proton Calendar Select the "Mail Plus" or "Proton Unlimited" paid plans for more features.
Tuta Tuta: Free, Cross-Platform and Zero-Knowledge Calendar
SilentSuite End-to-end encrypted sync for calendars, contacts, and tasks, wired into the apps you already use over CalDAV.
Radicale A simple self-hosted CalDAV and CardDAV server for calendars and contacts, written in Python and licensed under GPLv3.
Peergos Audited by Cure53 in May 2019.
EteSync license, in plain English
AGPL-3.0 Strong copyleft · network
Free to use, even commercially. Changes must be published under the same license, and running a modified version as a network service counts as distributing it.
Permits
- Commercial use
- Modification
- Distribution
- Patent use
- Private use
Requires
- Disclose source
- Network use is distribution
- Same license
- State changes
- License and copyright notice
Does not provide
- Liability cover
- Warranty
Why it matters: The network clause is the point. Anyone who runs a modified version as a hosted service has to publish those changes, so the code handling your data stays inspectable. This is why privacy-first projects reach for AGPL.
Plain-language summary of the project's license, not legal advice. Read the full text for the exact terms.
* Average ratings will show on this page once the threshold of 5 ratings is reached.