# Tuta Calendar (open-source calendar and contacts app)

> Tuta Calendar is a free, open-source calendar and contacts app for Android and iOS. Quantum-safe encrypted planner to schedule & manage your events & sync calendars. It has 7,986 GitHub stars and is released under the GPL-3.0-or-later license, and you can install it from F-Droid, Google Play and the App Store.

Take your privacy to the next level with the secure Tuta Calendar app. This encrypted time-management tool is the most private way to organize your busy schedule – and it’s quick to navigate, comes with dark and light mode, plus, it’s perfectly integrated with the Tuta Mail app. SECURE CALENDAR * Quantum-safe encryption: End-to-end encrypted data exchange with all Tuta Calendar users and with users of other calendar apps (via optional password-protected event invites). * No ads, no tracking, and no data sharing: We protect your privacy. * Zero-knowledge architecture: Entire events, including event notifications, are encrypted and hidden from our servers.

## Key facts

| Fact | Value |
|---|---|
| Repository | https://github.com/tutao/tutanota |
| Platforms | Android, iOS |
| Built with | Other |
| GitHub stars | 7,986 |
| License | GPL-3.0-or-later (open source) |
| F-Droid | https://f-droid.org/packages/de.tutao.calendar/ (package de.tutao.calendar) |
| F-Droid anti-features | Relies on a non-free network service |
| Google Play | https://play.google.com/store/apps/details?id=de.tutao.tutanota |
| App Store | https://apps.apple.com/app/id922429609 |
| Website | https://tuta.com |
| Official | yes (published by the organization behind the product) |
| Category | Calendar & contacts |
| Latest release | tutamail-nextcloud-release-1.2.3612610060 (Oct 6, 2026) |
| Last commit | Oct 6, 2026 |

F-Droid builds its apps from source and flags anti-features: https://f-droid.org/en/docs/Anti-Features/

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Canonical page: https://appsgit.com/mobile-apps/tuta-calendar
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