Best KOrganizer Alternatives in 2026
Updated
20 platforms from calendar apps ranked against KOrganizer on the same published basis.
- 1KOrganizer vs Lark
- 2KOrganizer vs Calendar.com
- 3KOrganizer vs Teamup
- 4KOrganizer vs 7shifts
- 5KOrganizer vs Slotly
- 6KOrganizer vs Mozilla Thunderbird
- 7KOrganizer vs Microsoft Outlook Calendar
- 8KOrganizer vs Proton Calendar
- 9KOrganizer vs Reclaim AI
- 10KOrganizer vs EGroupware
- 11KOrganizer vs Notion Calendar
- 12KOrganizer vs Doodle
- 13KOrganizer vs Cozi
- 14KOrganizer vs Google Calendar
- 15KOrganizer vs Tuta Calendar
- 16KOrganizer vs Fantastical
- 17KOrganizer vs FlowSavvy
- 18KOrganizer vs Samsung Calendar
- 19KOrganizer vs TimeTree
- 20KOrganizer vs DayFront
KOrganizer alternatives compared
| # | Platform | Score | Free plan | From | Runs on |
|---|---|---|---|---|---|
| 1 | Lark | 8.8 | Free plan | — | Android, API, iOS, Linux, Mac, Web, Windows |
| 2 | Calendar.com | 8.8 | Free plan | $20/mo | Android, API, Browser, iOS, Web |
| 3 | Teamup | 8.7 | Free plan | $12/mo | Android, API, iOS, Web |
| 4 | 7shifts | 8.1 | Free plan | Free | Android, API, iOS, Web |
| 5 | Slotly | 7.9 | Free plan | $0.83/mo | Android, API, Web |
| 6 | Mozilla Thunderbird | 7.6 | Free plan | Free | Android, Linux, Mac, Windows |
| 7 | Microsoft Outlook Calendar | 7.5 | Free plan | $1.67/mo | Android, iOS, Mac, Web |
| 8 | Proton Calendar | 7.4 | Free plan | Free | Android, iOS |
| 9 | Reclaim AI | 7.4 | Free plan | $10/mo | Browser, Web |
| 10 | EGroupware | 7.4 | No | €21.90/mo | Web, Linux, Windows, Mac |
| 11 | Notion Calendar | 7.3 | Free plan | Free | Android, iOS |
| 12 | Doodle | 7.3 | Free plan | $11/mo | Web |
| 13 | Cozi | 7.3 | Free plan | $3.25/mo | Android, iOS, Web |
| 14 | Google Calendar | 7.2 | No | $7/mo | Android, iOS |
| 15 | Tuta Calendar | 7.2 | Free plan | €3/mo | Android, iOS |
| 16 | Fantastical | 7.2 | Free plan | Free | iOS |
| 17 | FlowSavvy | 7.2 | Free plan | — | Android, iOS, Web |
| 18 | Samsung Calendar | 7.1 | Free plan | Free | Android |
| 19 | TimeTree | 7.1 | Free plan | $4.49/mo | Android, iOS |
| 20 | DayFront | 7.1 | No | — | API, self-hosted, Web |
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Questions about KOrganizer alternatives
What is the best alternative to KOrganizer?
Lark, number 1 in calendar apps with a score of 8.8 out of 10. The others here: Calendar.com, Teamup, 7shifts and 16 more.
What is the best free alternative to KOrganizer?
Lark is the best-ranked alternative with a free plan. 17 of the 20 alternatives here publish a free plan on their own pricing pages.
Is there an open-source alternative to KOrganizer?
Yes: Mozilla Thunderbird, EGroupware.
How are these alternatives ranked?
Ranked on what each maker publishes, open and connectable first: a public API, open-source code, the depth of its documentation and a free tier to try it on. Model lists are sorted by the figure in their title, exactly as each provider publishes it.