Proton Calendar

Proton Calendar is a privacy-first calendar service from Proton that keeps your schedule encrypted and under your control. It protects event details with end-to-end encryption, so titles, descriptions, locations, and attendees remain private even from Proton. Based in Switzerland, it offers a free calendar for individuals and paid plans for teams, with seamless integration into Proton’s privacy-focused ecosystem.

• End-to-end encryption of all event data (title, description, location, attendees)
• Zero-knowledge encryption for events from calendars outside Proton
• Cross-device sync across web, Android, and iOS
• Calendar sharing and collaboration (via paid plan)
• Multiple calendars, recurring events, reminders, and customizable views
• Ad-free experience with user-controlled access and themes (e.g., dark mode)
• Open source and independently audited
• Easy migration from other providers with Proton Easy Switch
• Integration with Proton Mail for managing invites from inbox
• Central account for all Proton services (Calendar, Mail, Drive, etc.)

• Privacy-first design: end-to-end encryption keeps your schedule private from advertisers and even Proton
• Swiss privacy protections: Proton is based in Switzerland with strong privacy laws
• Open source and independently audited: transparency and security verification
• Ad-free and data-minimizing: no tracking or targeted ads in your calendar
• Easy collaboration for business: secure team calendars and encrypted invitations
• Seamless integration with Proton’s ecosystem: single account access across Mail, Drive, VPN, and more

• Free calendar available at no cost for individual use
• Paid plans unlock collaboration, more calendars, and additional business features
• Pricing typically shown in CHF, EUR, and USD with standard subscription options and automatic renewals