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Fossify Calendar alternatives: 4 apps ranked by verified data

Facts checked Oct 25, 2026AppBreakup editorialHow we rank

Common reasons people leave Fossify Calendar: android only, and no built-in sync service. We ranked 4 alternatives by how directly each one replaces Fossify Calendar, then by reviews, real visits and how recently each app's facts were checked against its own website. Proton Calendar currently ranks first.

Quick comparison

#AppPricingOpen sourcePlatformsVerified factsScore
1Proton Calendar logoProton CalendarFree plan + paidYesWeb, iOS, Android +34 of 466.5
2Tuta Calendar logoTuta CalendarFree plan + paidYesWeb, iOS, Android +34 of 462.6
3Google Calendar logoGoogle CalendarFree plan + paidNoWeb, iOS, Android4 of 459.6
4KOrganizer logoKOrganizerOpen sourceYesLinux4 of 457.2
  1. Proton Calendar logo

    1. Proton CalendarTop pick

    Best for: Privacy-minded people and teams who want encrypted calendars, ideally with Proton Mail

    Free plan + paidOpen sourceWeb, iOS, Android, macOS, Windows, Linux

    66.5

    score / 100

    Why switch from Fossify Calendar

    Encrypted cloud sync across devices if you need more than a local calendar.

    Pros

    • End-to-end encrypted event details
    • Swiss jurisdiction and open-source apps
    • Free plan, bundled with Proton Mail on paid plans

    Cons

    • No direct CalDAV sync with third-party clients
    • Fewer integrations than Google Calendar
    • Best value only if you use other Proton apps
    Visit Proton Calendar Details and reviews
    How this score is calculated
    Editorial fit ×0.3100
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Proton Calendar a good Fossify Calendar alternative?

    Verified facts

    4 of 4 verified
    End-to-end encryption
    Yes
    Checked Oct 25, 2026proton.me(opens source in a new tab)
    Jurisdiction
    Switzerland
    Checked Oct 25, 2026proton.me(opens source in a new tab)
    Desktop apps
    macOS, Windows, Linux
    Checked Oct 25, 2026proton.me(opens source in a new tab)
    Free plan
    Yes
    Checked Oct 25, 2026proton.me(opens source in a new tab)
  2. Tuta Calendar logo

    2. Tuta Calendar

    Best for: Privacy-focused users who want an encrypted calendar with open-source apps

    Free plan + paidOpen sourceWeb, iOS, Android, Windows, macOS, Linux

    62.6

    score / 100

    Why switch from Fossify Calendar

    Encrypted calendar with an APK available outside Google Play.

    Pros

    • Encrypted calendar with open-source clients
    • Apps on every major platform, including Linux
    • Android APK available outside Google Play

    Cons

    • Free plan limited to one calendar
    • No CalDAV sync with other calendar apps
    • Basic features compared with mainstream calendars
    Visit Tuta Calendar Details and reviews
    How this score is calculated
    Editorial fit ×0.387
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Tuta Calendar a good Fossify Calendar alternative?

    Verified facts

    4 of 4 verified
    Mobile apps
    Free, Android and iPhone
    Checked Oct 25, 2026tuta.com(opens source in a new tab)
    Desktop clients
    Open source for Windows, macOS, Linux
    Checked Oct 25, 2026tuta.com(opens source in a new tab)
    Free plan calendars
    1
    Checked Oct 25, 2026tuta.com(opens source in a new tab)
    Android APK
    Available from GitHub
    Checked Oct 25, 2026tuta.com(opens source in a new tab)
  3. Google Calendar logo

    3. Google Calendar

    Best for: Anyone on Gmail or Google Workspace who wants a reliable free shared calendar

    Free plan + paidWeb, iOS, Android

    59.6

    score / 100

    Why switch from Fossify Calendar

    Seamless sync and sharing, at the cost of privacy.

    Pros

    • Free, fast sync across web, Android and iOS
    • Easy sharing and invitations with Meet links
    • Built-in appointment booking page

    Cons

    • No official desktop app for Windows or Mac
    • Not end-to-end encrypted
    • Fuller booking features need a paid plan
    Visit Google Calendar Details and reviews
    How this score is calculated
    Editorial fit ×0.377
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Google Calendar a good Fossify Calendar alternative?

    Verified facts

    4 of 4 verified
    Platforms
    Web, Android, iOS, Wear OS, Apple Watch
    Checked Oct 25, 2026workspace.google.com(opens source in a new tab)
    Free booking page
    One, with a personal Google account
    Checked Oct 25, 2026workspace.google.com(opens source in a new tab)
    Premium appointment scheduling
    Certain Google One and Workspace plans
    Checked Oct 25, 2026workspace.google.com(opens source in a new tab)
    Multiple calendars
    Yes
    Checked Oct 25, 2026workspace.google.com(opens source in a new tab)
  4. KOrganizer logo

    4. KOrganizer

    Best for: KDE Plasma users who want a configurable desktop calendar with tasks and journals

    Open sourceLinux

    57.2

    score / 100

    Why switch from Fossify Calendar

    Open-source desktop calendar for KDE users with CalDAV support.

    Pros

    • Events, to-dos and journal in one app
    • Integrates with KMail and the Kontact suite
    • Supports CalDAV, Google and groupware servers

    Cons

    • Dense, old-fashioned interface
    • Akonadi backend can be heavy to run and configure
    • Pulls in many KDE dependencies on other desktops
    Visit KOrganizer Details and reviews
    How this score is calculated
    Editorial fit ×0.369
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is KOrganizer a good Fossify Calendar alternative?

    Verified facts

    4 of 4 verified
    License
    GPL-2.0+
    Checked Oct 25, 2026apps.kde.org(opens source in a new tab)
    Part of
    Kontact suite
    Checked Oct 25, 2026apps.kde.org(opens source in a new tab)
    Features
    Events, tasks, alarms, web export
    Checked Oct 25, 2026apps.kde.org(opens source in a new tab)
    Platform
    Linux
    Checked Oct 25, 2026apps.kde.org(opens source in a new tab)

The best Fossify Calendar alternative for…

The highest-ranked app in this list for each need.

Proton Calendar logo

Best Fossify Calendar alternative for most people

Proton Calendar

Encrypted cloud sync across devices if you need more than a local calendar.

KOrganizer logo

Best Fossify Calendar alternative for a free option

KOrganizer

Open-source desktop calendar for KDE users with CalDAV support.

Tuta Calendar logo

Best Fossify Calendar alternative for a free plan you can upgrade

Tuta Calendar

Encrypted calendar with an APK available outside Google Play.

Proton Calendar logo

Best Fossify Calendar alternative for open source

Proton Calendar

Encrypted cloud sync across devices if you need more than a local calendar.

Proton Calendar logo

Best Fossify Calendar alternative for Mac

Proton Calendar

Encrypted cloud sync across devices if you need more than a local calendar.

Proton Calendar logo

Best Fossify Calendar alternative for Windows

Proton Calendar

Encrypted cloud sync across devices if you need more than a local calendar.

Proton Calendar logo

Best Fossify Calendar alternative for Linux

Proton Calendar

Encrypted cloud sync across devices if you need more than a local calendar.

Google Calendar logo

Best Fossify Calendar alternative for iPhone and Android

Google Calendar

Seamless sync and sharing, at the cost of privacy.

Proton Calendar logo

Best Fossify Calendar alternative for working in the browser

Proton Calendar

Encrypted cloud sync across devices if you need more than a local calendar.

Fossify Calendar alternatives: common questions

What is the best alternative to Fossify Calendar?

Proton Calendar ranks first right now. Encrypted cloud sync across devices if you need more than a local calendar. Tuta Calendar and Google Calendar follow it in our ranking.

Is there a free alternative to Fossify Calendar?

Yes. Proton Calendar (free plan + paid), Tuta Calendar (free plan + paid), Google Calendar (free plan + paid) and KOrganizer (open source) have a free option. Check each app's verified facts for current plan limits.

Is there an open-source alternative to Fossify Calendar?

Yes: Proton Calendar, Tuta Calendar and KOrganizer.

Which Fossify Calendar alternatives work on Linux?

Proton Calendar, Tuta Calendar and KOrganizer run on Linux.

Why do people switch from Fossify Calendar?

The complaints we hear most: android only; no built-in sync service; plain interface.

How is this list ranked?

Every app is scored with the same published formula: how directly it replaces Fossify Calendar, reviews (weighted by verification), visits from AppBreakup, how recently its facts were checked against its own website, and reader votes.