---
title: Kalendersynkronisering
icon: material/calendar
description: Calendars contain some of your most sensitive data; use products that implement encryption at rest.
cover: calendar.webp
---

<small>Protects against the following threat(s):</small>

- [:material-bug-outline: Passiva attacker](basics/common-threats.md#security-and-privacy ""){.pg-orange}
- [:material-server-network: Tjänsteleverantörer](basics/common-threats.md#privacy-from-service-providers ""){.pg-teal}

**Calendars** contain some of your most sensitive data; use products that implement end-to-end encryption at rest to prevent a provider from reading them.

## Tuta

<div class="admonition recommendation" markdown>

![Tuta logo](assets/img/email/tuta.svg#only-light){ align=right }
![Tuta logo](assets/img/email/tuta-dark.svg#only-dark){ align=right }

**Tuta** offers a free and encrypted calendar across their supported platforms. Features include automatic E2EE of all data, sharing features, import/export functionality, multifactor authentication, and [more](https://tuta.com/calendar-app-comparison).

Multiple calendars and extended sharing functionality are limited to paid subscribers.

[:octicons-home-16: Homepage](https://tuta.com/calendar){ .md-button .md-button--primary }
[:octicons-eye-16:](https://tuta.com/privacy){ .card-link title="Privacy Policy" }
[:octicons-info-16:](https://tuta.com/support){ .card-link title="Documentation" }
[:octicons-code-16:](https://github.com/tutao/tutanota){ .card-link title="Source Code" }
[:octicons-heart-16:](https://tuta.com/community#donate){ .card-link title="Contribute" }

<details class="downloads" markdown>
<summary>Downloads</summary>

- [:simple-googleplay: Google Play](https://play.google.com/store/apps/details?id=de.tutao.calendar)
- [:simple-appstore: App Store](https://apps.apple.com/app/id6657977811)
- [:simple-github: GitHub](https://github.com/tutao/tutanota/releases?q=Calendar)
- [:fontawesome-brands-windows: Windows](https://tuta.com/blog/desktop-clients)
- [:simple-apple: macOS](https://tuta.com/blog/desktop-clients)
- [:simple-linux: Linux](https://tuta.com/blog/desktop-clients)
- [:simple-flathub: Flathub](https://flathub.org/apps/com.tutanota.Tutanota)
- [:octicons-browser-16: Web](https://app.tuta.com)

</details>

</div>

## Proton Calendar

<div class="admonition recommendation" markdown>

![Proton](assets/img/calendar/proton-calendar.svg){ align=right }

**Proton Calendar** is an encrypted calendar service available to Proton members via its web or mobile clients. Features include automatic E2EE of all data, sharing features, import/export functionality, and [more](https://proton.me/support/proton-calendar-guide).

Those on the free tier have access to 3 calendars, whereas paid subscribers can create up to 25 calendars. Extended sharing functionality is also limited to paid subscribers.

[:octicons-home-16: Homepage](https://proton.me/calendar){ .md-button .md-button--primary }
[:octicons-eye-16:](https://proton.me/calendar/privacy-policy){ .card-link title="Privacy Policy" }
[:octicons-info-16:](https://proton.me/support/calendar){ .card-link title="Documentation" }
[:octicons-code-16:](https://github.com/orgs/ProtonMail/repositories?q=calendar){ .card-link title="Source Code" }

<details class="downloads" markdown>
<summary>Downloads</summary>

- [:simple-googleplay: Google Play](https://play.google.com/store/apps/details?id=me.proton.android.calendar)
- [:simple-appstore: App Store](https://apps.apple.com/app/id1514709943)
- [:octicons-browser-16: Web](https://calendar.proton.me)

</details>

</div>

In 2021, Securitum [audited](https://proton.me/community/open-source#:~:text=Proton%20Calendar) Proton Calendar's web client and provided a [letter of attestation](https://res.cloudinary.com/dbulfrlrz/images/v1714639870/wp-pme/letter-of-attestation-proton-calendar-20211109_3138998f9b/letter-of-attestation-proton-calendar-20211109_3138998f9b.pdf) for the Android app.

## Kriterier

**Observera att vi inte är knutna till något av de projekt som vi rekommenderar.** Förutom [våra standardkriterier](about/criteria.md)har vi utvecklat en tydlig uppsättning krav som gör det möjligt för oss att ge objektiva rekommendationer. Vi föreslår att du bekantar dig med den här listan innan du väljer att använda ett projekt, och att du gör din egen forskning för att se till att det är rätt val för dig.

### Minimikrav

- Must sync and store information with E2EE to ensure data is not visible to the service provider.

### Bästa fall

Våra kriterier för bästa fall representerar vad vi skulle vilja se av det perfekta projektet i denna kategori. Våra rekommendationer kanske inte innehåller alla eller några av dessa funktioner, men de som gör det kan vara högre rankade än andra på den här sidan.

- Should integrate with native OS calendar and contact management apps if applicable.
