Best European Online Calendars (2026): 11 Calendars Compared

The best European online calendar is Proton Calendar (Switzerland): free to start, encrypted end to end and available on every device. For a German calendar with even stronger encryption, choose Tuta Calendar; for a free calendar inside a full Swiss suite, Infomaniak kSuite.

An online calendar holds your appointments, your meetings and often your location for months ahead, so where it is stored matters. This is my ranking of every European calendar service I would recommend – personal calendars, shared group calendars, sync services and self-hosted software. If you are leaving Google specifically, the deeper comparison is in Best European alternatives to Google Calendar. I compared thirteen calendar services from European companies and kept eleven.

What are the best European online calendars?

Here are the eleven calendars in order, with the one job each does best. Every one is reviewed below.

1. Proton Calendar (Switzerland) – encrypted calendar with apps and a free plan. Best overall.
2. Tuta Calendar (Germany) – quantum-safe encryption from €3 a month. Best for privacy on a budget.
3. Infomaniak kSuite (Switzerland) – free calendar with mail, drive and video calls. Best free suite.
4. mailbox.org (Germany) – calendar, contacts and tasks that sync with any phone. Best for your existing calendar app.
5. Kolab Now (Switzerland) – Swiss groupware with ActiveSync and CalDAV. Best for Outlook users.
6. Nextcloud Calendar (Germany) – open-source and self-hosted. Best for full control.
7. Calendar.online (Germany) – shared calendars without a login. Best for clubs and families.
8. Teamup Calendar (Switzerland) – group calendar with sub-calendars, hosted in the US and Ireland. Best for team schedules.
9. Posteo (Germany) – encrypted CalDAV calendar for €1 a month. Best cheap private calendar.
10. fruux (Germany) – CalDAV and CardDAV sync service. Best sync backend.
11. Morgen (Switzerland) – a planner app on top of your existing calendars. Best for time blocking.

European online calendars compared

Prices from public pricing pages. Affiliate links and sponsored placements are labelled.

“Data hosted in” shows where each service stores your calendar data, based on its own statements, a DNS lookup of its domain and an ASN lookup (25 Oct 2026).

How I chose the best European online calendars

I looked at thirteen calendar services from companies in the EU and Switzerland and kept eleven. The order follows how complete each one is as an everyday calendar, then privacy and data sovereignty, then price. I weighed five things:

• Calendar features – free plan, apps, invitations, sharing, multiple calendars and import.
• Jurisdiction and hosting – where the company is registered and where events are stored, including any US cloud.
• Privacy – end-to-end encryption, open-source code and a business model without ads.
• Compatibility – CalDAV, ActiveSync and support for Apple Calendar, Outlook or Thunderbird.
• Price and user ratings – the cheapest useful plan and Trustpilot scores read with their review counts.

I left out Vivaldi’s calendar, because it is built into the Vivaldi browser rather than offered as a calendar service, and I did not list Infomaniak’s calendar separately from Infomaniak kSuite, because it only comes as part of that suite. All data comes from the providers’ own pricing, about, legal and privacy pages and from Trustpilot, checked on 25 October 2026.

The best European online calendars, reviewed

For each calendar: who is behind it, what users say, what it offers and what it lacks, the key facts, pros and cons, and my take.

1. Proton Calendar

The most complete European calendar – encrypted, free to start and on every device

Proton AG in Plan-les-Ouates near Geneva makes Proton Calendar. Proton was founded in 2014 by scientists who met at CERN, and the non-profit Proton Foundation is its primary shareholder. The calendar runs on Proton’s own network (AS62371) under Swiss law. Full review →

What users say. The calendar has no Trustpilot profile of its own; the Proton Mail profile has 2.1/5 from 1,802 reviews, with most complaints about support and lockouts.

What it offers – and what it lacks. End-to-end encryption of titles, descriptions, locations and participants, apps for iPhone, Android, Windows, macOS, Linux and the web, invitations from Proton Mail and an import from Google and other providers through Easy Switch. Paid plans add sharing, up to 25 calendars and a booking page. It lacks CalDAV on its product page and gives free users only 3 calendars.

Facts: Switzerland · founded 2014 · free: 3 calendars · Mail Plus $3.99/month billed yearly · open source with an audit report.

My take: Proton Calendar is the one I would give to anyone: it is as easy as the big US calendars and Proton cannot read your events. Being part of a full suite with mail and drive makes it first. Best for: most people who want a private everyday calendar. Not for: people tied to their phone's built-in calendar app.

Visit proton.me →

2. Tuta Calendar

Zero-knowledge, quantum-safe calendar from Hanover

Tutao GmbH in Hanover runs Tuta, which started as a secure email service in 2011 and now includes an encrypted calendar and address book. Tuta hosts on its own network (AS210909) in Germany.

What users say. Tuta has 3.5/5 from 392 reviews on Trustpilot – a company-wide profile that is mostly about email.

What it offers – and what it lacks. Events, invitations and sharing are encrypted end to end with quantum-safe encryption, and push reminders are hidden from your phone’s operating system. Apps exist for iPhone, iPad, Android, Windows, macOS, Linux and the browser, and paid plans share calendars with three levels of access. It lacks a direct Google import, CalDAV on its product page, and sharing on the free plan.

Facts: Germany · started 2011 · free: 1 calendar · Revolutionary €3/month billed yearly, unlimited calendars · open-source desktop clients.

My take: Tuta is the most private calendar in Europe at the lowest price. The bare free plan keeps it just behind Proton. Best for: privacy-first users on a budget. Not for: families who need free shared calendars.

Visit tuta.com →

3. Infomaniak kSuite

A free Swiss suite where the calendar comes with mail, drive and video calls

Infomaniak Network SA develops and hosts kSuite in Switzerland on its own network (AS29222). The free my kSuite plan includes an email address, 20 GB of mail storage, kDrive, kMeet and a calendar.

What users say. Infomaniak has 4.0/5 from 2,069 reviews on Trustpilot, covering all its products.

What it offers – and what it lacks. A calendar that syncs meetings and contacts across your devices, inside a suite that replaces a whole Google or Microsoft account. my kSuite+ removes the calendar limit and adds 30-day restoration. It lacks end-to-end encryption and gives free users one calendar.

Facts: Switzerland · free: 1 calendar · my kSuite+ CHF 19/year, unlimited calendars · prices shown excluding VAT · own Swiss infrastructure.

My take: Infomaniak gives you the most for nothing, and the paid plan is a bargain. Without end-to-end encryption it ranks third. Best for: people replacing a whole Google account for free. Not for: those who want encrypted events.

Visit infomaniak.com →

4. mailbox.org

German groupware that puts a European account behind your phone’s calendar app

mailbox.org belongs to the German Heinlein Group. Every plan includes calendar and contacts, tasks, mobile sync and sharing of calendars and appointments.

What users say. mailbox.org has 4.2/5 from 229 reviews on Trustpilot, the best score here with a meaningful number of reviews.

What it offers – and what it lacks. Sync with the calendar apps already on your phone and computer, sharing on every plan, and on Standard an office suite, video meetings, 10 GB of cloud storage and family accounts. It lacks a free plan and end-to-end encryption for events.

Facts: Germany · 30-day free trial · Light €1/month (€12/year), Standard €3/month billed yearly · prices include VAT.

My take: mailbox.org is the quiet favourite of people who want things to just sync. It would rank higher with a free plan. Best for: people who like their phone's calendar app. Not for: anyone who needs a free calendar.

Visit mailbox.org →

5. Kolab Now

Groupware on its own Swiss infrastructure since 2013

Apheleia IT AG in Bern runs Kolab Now, owned and operated in Switzerland since 2013 on its own infrastructure, on the network of NTS workspace AG (AS15576).

What users say. There are no reviews of Kolab Now on Trustpilot yet.

What it offers – and what it lacks. The full Kolab plan bundles calendar, tasks, notes, file storage, collaborative documents and meeting rooms, with ActiveSync and CalDAV/CardDAV for phones and Outlook. It lacks a free plan, and the calendar is not in the cheaper email-only plan.

Facts: Switzerland (Bern) · since 2013 · 30 days free · full kolab CHF 9.90/month · ActiveSync and CalDAV/CardDAV.

My take: Kolab Now is a grown-up groupware service with Swiss hosting. It costs more than a calendar alone should. Best for: small businesses working in Outlook. Not for: individuals who only need a calendar.

Visit kolabnow.com →

6. Nextcloud Calendar

The open-source calendar for your own server

Nextcloud GmbH, headquartered in Stuttgart with its main office in Berlin, makes Nextcloud Groupware. It is open source and self-hosted, so events stay on infrastructure you control.

What users say. Nextcloud has 2.6/5 from 52 reviews on Trustpilot, a company-wide profile.

What it offers – and what it lacks. A web calendar with contacts and mail, native integration into iOS, Android, macOS, Windows, Linux, Outlook and Thunderbird, holiday calendars and automatic Talk video rooms for appointments. It lacks a ready-made service: someone has to run it.

Facts: Germany (Stuttgart) · open source · free to self-host · hosted wherever you run it.

My take: Nextcloud is the answer to who holds my calendar: you do. It is software, not a service, which is why it sits sixth. Best for: organisations and tech-savvy users. Not for: people who want a calendar that works out of the box.

Visit nextcloud.com →

7. Calendar.online

Shared calendars that guests open with a link, on German servers

Kalender.digital GmbH in Düsseldorf runs Calendar.online. It says all servers are in Germany; its domain runs on Hetzner (AS24940).

What users say. There are no reviews of Calendar.online on Trustpilot yet.

What it offers – and what it lacks. Sub-calendars, access links with read or write rights, unlimited users, booking links, reminders, iCalendar import and export, and apps for Android, iOS and macOS. It lacks end-to-end encryption and is not meant as a personal calendar with email invitations.

Facts: Germany (Düsseldorf) · free: 6 sub-calendars, 3 access links, unlimited users · Plus $6.90 per calendar per month · servers in Germany.

My take: Calendar.online is the simplest way to give a group one schedule. As a personal calendar it falls short. Best for: clubs, schools and families. Not for: people looking for a personal calendar.

Visit calendar.online →

8. Teamup Calendar

A Swiss group calendar with data hosted in the US and Ireland

Teamup Solutions AG in Zurich provides Teamup under Swiss law. Its privacy policy says data is hosted in Oregon (United States) and Dublin (Ireland), and the app domain runs on Amazon’s network (AS16509).

What users say. Teamup has 4.0/5 on Trustpilot from only 4 reviews, praising easy setup and sharing.

What it offers – and what it lacks. A master calendar with colour-coded sub-calendars, custom fields, access rights and iCal feeds – built for teams that share one schedule. It lacks European hosting and a personal calendar tied to your email.

Facts: Switzerland (Zurich) · free: 5 sub-calendars, 5 users · Plus $12/month billed yearly · data in the USA and Ireland.

My take: Teamup is excellent at group scheduling, but Oregon hosting means it does not keep your data in Europe. Best for: teams sharing one schedule. Not for: anyone who wants their data out of the US.

Visit teamup.com →

9. Posteo

An encryptable CalDAV calendar for €1 a month

Posteo is a German email provider that charges 1 EUR a month and does not ask for personal details at sign-up. Every account includes a calendar.

What users say. Posteo has 3.1/5 from 194 reviews on Trustpilot.

What it offers – and what it lacks. A web calendar, CalDAV sync with most devices, three included calendars (€0.10 a month for each extra one) and optional AES encryption protected by your password. It lacks a free plan, its own app, and sharing while encryption is on.

Facts: Germany · €1/month · 3 calendars included · CalDAV · optional AES encryption.

My take: Posteo is honest and cheap, and the password-protected calendar is a rare feature. It is a mailbox first, so it sits ninth. Best for: a cheap private calendar for your phone's app. Not for: families sharing encrypted calendars.

Visit posteo.de →

10. fruux

CalDAV and CardDAV sync for calendars, contacts and tasks

fruux GmbH in Münster, managed by Dominik Tobschall, runs fruux; its copyright line goes back to 2007. fruux says data is encrypted and backed up on servers in Germany, but its domains run on Amazon Web Services (AS16509).

What users say. There are no reviews of fruux on Trustpilot yet.

What it offers – and what it lacks. Unlimited calendars, contacts and tasks synced over CalDAV and CardDAV, with sharing, free-busy scheduling, delegation and public calendars. It lacks a full web app – fruux says many features need a compatible calendar app.

Facts: Germany (Münster) · free: Basic, 2 shares, 2 devices · Pro €4/month or €40/year · Team €20/month for 5 members · runs on AWS.

My take: fruux is a solid sync backend for people who already have a calendar app they love. AWS hosting and a thin web app put it tenth. Best for: Apple Calendar and Thunderbird users. Not for: people who want a browser calendar.

Visit fruux.com →

11. Morgen

A Swiss planner app that combines your calendars and tasks

Morgen AG in Zurich makes Morgen, a calendar and AI planning app for Windows, macOS, Linux, mobile and the browser. It connects to Google, Outlook, iCloud and other calendars; Morgen says events are not stored on its servers, and its backend runs on Google Cloud in Switzerland and the EU. It has 4.4/5 from 71 reviews on Trustpilot. There is no free plan: Pro costs $15 a month billed yearly or $30 monthly, after a 14-day trial.

Facts: Switzerland (Zurich) · Pro $15/month billed yearly · 14-day trial · backend on Google Cloud (Switzerland and EU) · works with Google, Outlook and iCloud calendars.

Visit morgen.so →

What European online calendars cost

Prices as shown on each provider’s pricing page on 25 October 2026, in the currency shown there. Infomaniak states its prices excluding VAT.

How to choose a European online calendar

1. Decide who can read your events. If no one but you should, pick an end-to-end encrypted calendar: Proton or Tuta.
2. Check your apps. If you want to keep Apple Calendar, Outlook or Thunderbird, choose a service with CalDAV or ActiveSync, such as mailbox.org, Posteo, Kolab Now or fruux.
3. Think about sharing. For a family or club calendar that guests open with a link, Calendar.online is easiest; for team schedules, Teamup.
4. Look at where data is hosted. A European company is not always European hosting – Teamup and fruux use US-owned infrastructure.
5. Start on a free plan or trial. Most services here have one, so import a calendar and use it for a week before you pay.

European online calendars: FAQ

My verdict

For most people the best European online calendar is Proton Calendar: free to start, encrypted and as easy as the US giants. Choose Tuta Calendar if you want maximum privacy for €3 a month, and Infomaniak kSuite if you want a free calendar with mail and storage from one Swiss account.

If you want to keep your phone’s own calendar app, mailbox.org or Posteo are the cheapest European accounts behind it. Groups should look at Calendar.online, and anyone who wants total control should run Nextcloud.