The Best Open Source Google Calendar AlternativesTop Calendar Apps like Google Calendar

Alternatives list

1. 

   

   Etar

    88 likes

   Material design open source calendar for Android.

   Cost / License

   • Free
   • Open Source (GPL-3.0)

   Application type

   • Calendar

   Origin

   • Germany
   • EU

   Platforms

   • Android
   • Android Tablet
   • F-Droid

   • Germany
   • EU

   

   

   

   +8

   

   More about Etar  

   

   Good alternative?Is Etar a good alternative to Google Calendar?

    

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   5comments

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   Etar vs Google Calendar Comments

   Top Positive Comment by Guest · Nov 23, 2019

   Nice, clean, and to the point calendar!

   Top Negative Comment by paddling583 · Jul 2, 2024

   It has a terrible interface and the description lied about it being a material design. It also lacks export and sync.

   Negative comment by Guest · Jan 24, 2025

   does not conform to UNIX principles (let the application be one, but it will work well and cooperate with other functions and applications in the system); The interface is hideous. Nothing is anywhere, it's hard to figure out; It is not practical. Notion Calendar or Apple Calendar for example have a lot of common handy features that Etar doesn't have;

   3 of 5 comments

   

   

   • Etar is Free and Open SourceGoogle Calendar is Free Personal and Proprietary
   • Etar is Lightweight and Privacy focusedGoogle Calendar is not according to our users
2. 

   

   Fossify Calendar

    64 likes

   Your privacy-aware, open-source calendar with intuitive design and multi-platform syncing.

   68 Fossify Calendar alternatives

   Cost / License

   • Free
   • Open Source (GPL-3.0)

   Application type

   • Calendar

   Origin

   • India

   Platforms

   • Android
   • Android Tablet
   • F-Droid
   • OpenAPK

   • India

   

   

   

   More about Fossify Calendar  

   

   Good alternative?Is Fossify Calendar a good alternative to Google Calendar?

    

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   2comments

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   Fossify Calendar vs Google Calendar Comments

   Positive comment by amphetamachine · Jun 19, 2026

   Numerous outstanding bugs make Fossify Calendar not recommendable as a working alternative to Google Calendar. Some I've personally experienced: Often fails to display events in the calendar; Interprets event recurrence information incorrectly; Re-writes UIDs when importing, leading to duplicating events on re-import/update.

   Positive comment by Guest · Oct 6, 2024

   Customizable and you have control over your data.

   2 of 2 comments

   

   

   • Fossify Calendar is Free and Open SourceGoogle Calendar is Free Personal and Proprietary
   • Fossify Calendar is Privacy focused, Customizable and LightweightGoogle Calendar is not according to our users
4. 

   

   Calendar Lock PEA

    18 likes

   Calendar encryption: View calendars and stores them encrypted on your device or in the cloud.

   79 Calendar Lock PEA alternatives

   Cost / License

   • Free
   • Open Source

   Application type

   • Calendar

   Platforms

   • Mac
   • Windows
   • Linux

   

   

   

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   Good alternative?Is Calendar Lock PEA a good alternative to Google Calendar?

    
5. 

   

   Tuta Calendar

    50 likes

   Tuta Calendar offers secure event organization with end-to-end encryption and no ads or tracking. Enjoy multi-device sync, multiple calendar views, and offline access. Fully compliant with strict German data protection laws. Manage recurring events, unlimited calendars, and seamlessly integrate with Tuta Mail.

   Cost / License

   • Freemium
   • Open Source (GPL-3.0)

   Application type

   • Calendar

   Origin

   • Germany
   • EU

   Platforms

   • Online
   • Android
   • iPhone
   • Android Tablet
   • iPad
   • F-Droid
   • Thunderbird
   • OpenAPK

   • Germany
   • EU

   

   

   

   +4

   

   More about Tuta Calendar  

   

   Good alternative?Is Tuta Calendar a good alternative to Google Calendar?

    

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   1comment

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   Tuta Calendar vs Google Calendar Comments

   Positive comment by JOPloume · Apr 20, 2025

   End-to-end encryption and works across all platforms: for me, on Android, Mac, and Windows (and even via Browser)!

   1 of 1 comments

   

   

   • Tuta Calendar is Freemium and Open SourceGoogle Calendar is Free Personal and Proprietary
   • Tuta Calendar is Privacy focused, Lightweight and CustomizableGoogle Calendar is not according to our users
6. 

   

   Nextcloud Calendar

    34 likes

   Calendar interface for CalDAV enabling cross-device event sync, web-based editing, recurring events, Nextcloud Contacts integration, WebCal subscriptions, attendee invites, color coding, event notifications, privacy-focused hosting, and import/export support.

   47 Nextcloud Calendar alternatives

   Cost / License

   • Free
   • Open Source (AGPL-3.0)

   Application type

   • Calendar

   Origin

   • Germany
   • EU

   Platforms

   • Online
   • Self-Hosted
   • Nextcloud

   • Germany
   • EU

   

   More about Nextcloud Calendar  

   

   Good alternative?Is Nextcloud Calendar a good alternative to Google Calendar?

    

   |

   1comment

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   Nextcloud Calendar vs Google Calendar Comments

   Positive comment by Guest · Nov 30, 2019

   Free (and open source) alternative. Your data is yours !

   1 of 1 comments

   

   

   • Nextcloud Calendar is Free and Open SourceGoogle Calendar is Free Personal and Proprietary
   • Nextcloud Calendar is Privacy focusedGoogle Calendar is not according to our users
8. 

   

   KashCal

    9 likes

   A privacy-first calendar that works offline and looks beautiful. Connect to iCloud — or don't. Your schedule, your choice.

   57 KashCal alternatives

   Cost / License

   • Free
   • Open Source

   Application type

   • Calendar

   Platforms

   • Android
   • F-Droid

   

   

   

   More about KashCal  

   

   Good alternative?Is KashCal a good alternative to Google Calendar?

    
9. 

   

   fruux

    37 likes

   fruux is a free service that takes care of your contacts, calendars and more so you don't have to. Never manually copy contacts and calenders between your devices again!

   Cost / License

   • Freemium
   • Open Source

   Application type

   • Calendar

   Origin

   • Germany
   • EU

   Platforms

   • Mac
   • Windows
   • Linux
   • Online
   • Android
   • iPhone
   • Blackberry
   • Windows Phone
   • iPad
   • Blackberry 10
   • Sailfish OS
   • Software as a Service (SaaS)

   • Germany
   • EU

   

   More about fruux  

   

   Good alternative?Is fruux a good alternative to Google Calendar?

    
10. 

    

    Merkuro Calendar

     13 likes

    Merkuro is a calendar and contact application that allows you to manage your tasks, events and contacts. Merkuro supports both local calendars as well as a multitude of online calendars: Nextcloud, Google® Calendar, Outlook®, Caldav, and many more.

    123 Merkuro Calendar alternatives

    Cost / License

    • Free
    • Open Source

    Application typeApplication types

    • Todo List Manager
    • Calendar

    Origin

    • Germany
    • EU

    Platforms

    • Linux
    • Flathub
    • Flatpak
    • Linux Mobile

    • Germany
    • EU

    

    

    

    +5

    

    More about Merkuro Calendar  

    

    Good alternative?Is Merkuro Calendar a good alternative to Google Calendar?

     
11. 

    

    Right Calendar

     11 likes

    Right Calendar app is a versatile scheduling tool that offers unparalleled flexibility to its users. One of its standout features is that it is built on an open-source platform. This not only ensures transparency but also allows for constant updates and bug fixes from a...

    Cost / License

    • Free Personal
    • Open Source (GPL-3.0)

    Application typeApplication types

    • Calendar
    • Todo List Manager

    Origin

    • International

    Platforms

    • Android

    • Global

    

    

    

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    Good alternative?Is Right Calendar a good alternative to Google Calendar?

     
12. 

    

    Kolab

     43 likes

    Kolab provides a FOSS communication & collaboration solution that can be completely self-hosted. Take back control of your data and access it via the webinterface, or existing mobile & desktop clients.

    Cost / License

    • Freemium
    • Open Source

    Application type

    • Calendar

    Origin

    • Switzerland

    Platforms

    • Linux
    • Online
    • Self-Hosted

    

    Good alternative?Is Kolab a good alternative to Google Calendar?

     
13. 

    

    Kontact

     37 likes

    Personal Information Manager (Mail, Contact, Calendar and more).

    115 Kontact alternatives

    Cost / License

    • Free
    • Open Source

    Application typeApplication types

    • Calendar
    • Email Client

    Origin

    • Germany
    • EU

    Platforms

    • Linux
    • Flathub

    • Germany
    • EU

    

    More about Kontact  

    

    Good alternative?Is Kontact a good alternative to Google Calendar?

     
14. 

    

    Calendula

     3 likes

    A modern Material 3 Expressive calendar for Android. Reads, writes, and reminds — on top of the system calendar, with zero network access.

    Cost / License

    • Free
    • Open Source (MIT)

    Application type

    • Calendar

    Origin

    • Germany
    • EU

    Platforms

    • Android
    • Android Tablet
    • Obtainium
    • F-Droid

    • Germany
    • EU

    

    

    

    More about Calendula  

    

    Good alternative?Is Calendula a good alternative to Google Calendar?