khal
Calendar & ContactsCommand-line calendar built on CalDAV
Replaces Google Calendar
Best Offline-First Calendar & Contacts for self-hosting
The 6 best Offline-First calendar & contacts you can self-host, ranked by community traction.
DAVx5
Calendar & ContactsCalDAV/CardDAV sync client for Android
Replaces Google Calendar Sync, iCloud sync
vdirsyncer
Calendar & ContactsSynchronize calendars and contacts via CalDAV/CardDAV
Replaces iCloud sync
calcurse
Calendar & ContactsText-based calendar and scheduling application
Replaces Google Calendar
Decsync Calendar Sync
Calendar & ContactsFile-based calendar and contacts synchronization
Replaces Google Calendar
KOrganizer
Calendar & ContactsCalendar and scheduling component of KDE Kontact
Replaces Outlook Calendar
No apps match these filters.
At a glance
| App | Deploy effort | Difficulty | Min. RAM | License | ★ Stars |
|---|---|---|---|---|---|
| khal | Read-the-docs project | Medium | 64 MB | MIT | 3,073 |
| DAVx5 | Read-the-docs project | Easy | 128 MB | GPL-3.0 | 2,949 |
| vdirsyncer | Read-the-docs project | Medium | 64 MB | BSD-3-Clause | 1,888 |
| calcurse | Read-the-docs project | Easy | 16 MB | BSD-2-Clause | 1,308 |
| Decsync Calendar Sync | Read-the-docs project | Medium | 128 MB | GPL-3.0 | 702 |
| KOrganizer | Read-the-docs project | Medium | 512 MB | GPL-2.0 | 100 |
Quick picks
- Most adopted: khal (3,073 GitHub stars).
- Lightest footprint: calcurse (from 16 MB RAM, against 512 MB for the heaviest here).
- Licensing: 2 of 6 use GPL-3.0; check the rest individually if you plan to modify and redistribute.
Every option here is open-source and self-hostable, tagged Offline-First within the calendar & contacts category. Deploy effort is graded from published container recipes, not vendor claims — see the methodology.