Private and open-source alternatives to Google Calendar
10 calendars rated against the same public privacy criteria as Google Calendar, with our picks first.
Why look for an alternative?
- Open source: no. Closed source.
- No trackers or telemetry: no. Google collects activity data across its services and uses it for analytics and personalized ads.
- No ads or data sales: no. Free for personal accounts and funded by Google's advertising business, which uses activity data across services.
- Independent audit: partial. Google Workspace, which includes Calendar, has third-party SOC 2 audits. Only the SOC 3 summary report is public.
See the full Google Calendar rating.
The alternatives
Forward Email Calendar Grade B
CalDAV calendar, task and CardDAV contacts service included with paid Forward Email plans. It works with any CalDAV or CardDAV app and with Forward Email's own webmail, desktop and mobile apps, and stores data in each alias's encrypted SQLite mailbox.
Based in the United States (Five Eyes). Forward Email Calendar scores 85 out of 100 (grade B) on the calendars criteria. It meets 3 of 4 criteria: open source, no ads or data sales and independent audit.
Baïkal Grade B
Self-hosted CalDAV and CardDAV server written in PHP and built on the sabre/dav library, with a web interface for managing users, calendars and address books.
Baïkal scores 80 out of 100 (grade B) on the calendars criteria. It meets 3 of 4 criteria: open source, no trackers or telemetry and no ads or data sales.
DAVx⁵ Grade B
Android app that syncs calendars, contacts, tasks and files with CalDAV, CardDAV and WebDAV servers, so they appear in the device's own calendar and contacts apps.
Based in Austria. DAVx⁵ scores 80 out of 100 (grade B) on the calendars criteria. It meets 3 of 4 criteria: open source, no trackers or telemetry and no ads or data sales.
Etar Grade B
Open source Android calendar app based on the AOSP Calendar. Shows calendars stored on the device, including offline calendars and CalDAV calendars synced by an app such as DAVx5.
Etar scores 80 out of 100 (grade B) on the calendars criteria. It meets 3 of 4 criteria: open source, no trackers or telemetry and no ads or data sales.
Fossify Calendar Grade B
Offline Android calendar from Fossify, a community fork of Simple Mobile Tools. Supports widgets, reminders and ICS import and export, and can show CalDAV calendars synced by an app such as DAVx5.
Fossify Calendar scores 80 out of 100 (grade B) on the calendars criteria. It meets 3 of 4 criteria: open source, no trackers or telemetry and no ads or data sales.
KashCal Grade B
Offline-first Android calendar that syncs with iCloud, CalDAV and the device calendar. Needs no account, has no telemetry and stores credentials in the Android Keystore.
KashCal scores 80 out of 100 (grade B) on the calendars criteria. It meets 3 of 4 criteria: open source, no trackers or telemetry and no ads or data sales.
Nextcloud Calendar Grade B
Calendar app for self-hosted Nextcloud servers. Syncs across devices with CalDAV and supports shared calendars and appointment booking. No end-to-end encryption.
Based in Germany (Fourteen Eyes). Nextcloud Calendar scores 80 out of 100 (grade B) on the calendars criteria. It meets 3 of 4 criteria: open source, no trackers or telemetry and no ads or data sales.
Radicale Grade B
Lightweight self-hosted CalDAV and CardDAV server written in Python, for syncing calendars, contacts and task lists across devices. Stores data as plain files.
Radicale scores 80 out of 100 (grade B) on the calendars criteria. It meets 3 of 4 criteria: open source, no trackers or telemetry and no ads or data sales.
Tuta Calendar Grade C
End-to-end encrypted calendar from Tuta, available as a standalone Android and iOS app and in Tuta's web and desktop clients. Events, invitations and shared calendars are encrypted.
Based in Germany (Fourteen Eyes). Tuta Calendar scores 65 out of 100 (grade C) on the calendars criteria. It meets 2 of 4 criteria: no trackers or telemetry and no ads or data sales.
Proton Calendar Grade C
End-to-end encrypted calendar from Proton for web, Android and iOS. Supports shared calendars, recurring events, time zones, ICS import and subscriptions, and integrates with Proton Mail.
Based in Switzerland. Proton Calendar scores 60 out of 100 (grade C) on the calendars criteria. It meets 1 of 4 criteria: no ads or data sales.