📅 Calendar Open source Privacy ★★★★★
EteSync
E2EE CalDAV synchronization
Overview
EteSync wraps calendar, contacts, and tasks in E2EE while preserving CalDAV compatibility via its apps and DAVx5.
Self-host edition available—technical sweet spot between Proton Calendar and plain CalDAV.
Dedicated Android/iOS/Web apps plus standard CalDAV clients supported.
Scores
Privacy 5/5
Ease of use 3/5
Features 4/5
Value 4/5
Google Calendar — comparison
E2EE with CalDAV freedom—no Google account; use any CalDAV app you prefer.
Pros
- ✓ E2EE for Cal/Contacts/Tasks
- ✓ Works with existing CalDAV clients
- ✓ Open source; self-hostable
- ✓ Native mobile apps included
Cons & caveats
- − Extra CalDAV client configuration
- − Free tier: one device only
- − UI less polished than Google Calendar
Best for
- CalDAV plus E2EE together
- Technical users
- Self-hosting interest
Not ideal for
- Zero-configuration immediate use
- Google Calendar–clone UI seekers
Specs
- Pricing
- Free + paid — Free one-device tier. Premium $24/year unlimited devices. Self-host free.
- Difficulty
- Moderate
- Data location
- EteSync cloud (UK) or self-host; E2EE—server sees ciphertext only.
- Platforms
- Android · iOS · Desktop · Web · CalDAV clients
E2EE同期Cal/Contact/Tasks自己ホスト可
Migration from Google Calendar
- 1 Create EteSync account
- 2 Export Google .ics and import to EteSync
- 3 Connect DAVx5 on Android or iOS CalDAV settings
- 4 Verify multi-device sync
Setup steps
- 1 Register at etesync.com
- 2 Install EteSync app
- 3 Import Google Calendar .ics
- 4 Configure CalDAV URL on each client and test sync