Thunderbird vs KOrganizer: catalog facts
 Thunderbird |  KOrganizer |
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Free Free forever, funded by donations. |
Free Free and open source from the KDE community. |
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Windows, macOS, Linux, Android |
Linux |
- Unified inbox across every account, or each account kept separate, your choice
- Mail, calendar, contacts and tasks in one application rather than four
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- Works with Nextcloud, Kolab, Google Calendar and CalDAV servers
- Integrated to-dos alongside the agenda view
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- The interface carries a lot of history and can feel dense next to a webmail tab
- Major ESR releases have historically been disruptive for add-ons and settings
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- Best suited to the KDE Plasma desktop
- Depends on the Kontact/Akonadi stack
|
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Downloadable app |
Downloadable app |
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Open source |
Open source |
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License: MPL-2.0 |
License not stated |
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No account needed |
No account needed |
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Works offline |
Works offline |
Checked September 20, 2026 | Checked October 2, 2026 |
Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.
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