Proton Calendar review

Proton Calendar is the privacy option on this list. Its Android listing promises no ads, no trackers and no data sharing with third parties, with end-to-end encryption between Proton Calendar users and zero-access encryption for event names, descriptions and participants on Proton's servers. Proton says events received from people on other calendars are secured with zero-knowledge encryption, and invitations can be sent straight from a Proton Mail address. The app syncs across browsers and devices, supports recurring events and foreign time zones, offers several reminders per event, adds a home screen widget and includes private appointment scheduling. Paid plans raise the limit to 20 calendars. The catch for this list is account sync: Proton's Android listing describes its own encrypted calendar rather than a view of existing Google or Outlook accounts, so it is a replacement, not a hub. We could not confirm USD prices on Proton's pricing page from here.

Who it is for

People who want their schedule encrypted and kept away from ad-funded services.

Price

Free plan; paid plans: see vendor pricing (USD check pending).

US price check pending. See the vendor pricing page.

Key features

• End-to-end encryption between Proton Calendar users
• Zero-access encryption for event names, descriptions and participants
• Private appointment scheduling
• Home screen widget and multiple reminders per event
• Up to 20 calendars on paid plans

Strengths and weaknesses

• Strength: No ads and no trackers
• Strength: Based in Switzerland under Swiss privacy law
• Strength: Sends invitations from a Proton Mail address
• Weakness: Its Android listing does not describe syncing Google or Outlook accounts
• Weakness: Extra calendars are a paid feature
• Weakness: Fewer views and widgets than the Android specialists

Key facts

• Free plan: Yes
• Paid calendars: Up to 20
• Encryption: End-to-end and zero-access
• Headquarters: Switzerland

Where it ranks

Proton Calendar is No. 10 in our Best Calendar Apps for Android verdict and No. 9 in Best Desktop Calendar Apps and No. 7 in Best Free Calendar Apps.