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Proton Calendar

End-to-end encrypted calendar built for privacy-first scheduling

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  • Overview
  • Features
  • Pricing
  • Pros
  • Cons
  • Reviews

Proton Calendar Overview

  • Updated March 10, 2026

Proton Calendar is a secure, privacy-focused digital calendar developed by Proton AG in Switzerland. It uses end-to-end encryption to protect event details, invitations, and metadata so no third party, including Proton, can access your schedule.

It is an alternative to Big Tech calendars, it integrates tightly with Proton Mail and works across web and mobile platforms.

Key Features

  • End-to-End Encryption: All event details, locations, and attendees are encrypted so only you can read them.
  • Swiss Privacy Protection: Operates under strict Swiss privacy laws and neutrality.
  • Calendar Sharing: Securely share calendars with trusted contacts on paid plans.
  • Proton Mail Integration: Send invitations and create events directly from encrypted emails.
  • Cross-Platform Access: Available on web, Android, and iOS with consistent security.

Price

Plan Price Featured
Free $0 (Free) End-to-end encrypted events, Basic calendar access, Single user
Proton Unlimited $12.99/mo (Billed Monthly) / $9.99/mo ( Billed Annually) Calendar sharing, Priority support, Access to full Proton ecosystem
Proton Duo $19.99/mo (Billed Monthly) / $14.99/mo (Billed Annually) Two-user access, Shared encrypted storage, Premium privacy features

Price details: https://proton.me/pricing

Pros

Competitor

Pros
Google Calendar Proton Calendar offers true end-to-end encryption, unlike Google Calendar where data is accessible for advertising and analytics. It avoids data profiling entirely, provides stronger legal protection under Swiss law, and feels simpler for users who want scheduling without surveillance or ecosystem lock-in.
Microsoft Outlook Calendar Compared to Outlook Calendar, Proton Calendar is easier to use for privacy-focused individuals and does not rely on enterprise accounts. It avoids telemetry-heavy integrations, keeps metadata private, and delivers a cleaner interface without complex enterprise configuration.
Apple Calendar While Apple emphasizes privacy, Proton Calendar provides transparent, audited encryption and open-source components. It works consistently across platforms, not just Apple devices, making it more flexible for users outside the Apple ecosystem.
Zoho Calendar Proton Calendar is simpler to set up and focuses purely on personal privacy, whereas Zoho Calendar targets business workflows. Proton avoids data mining entirely and delivers stronger encryption by default without requiring administrative setup.
Tutanota Calendar Compared to Tutanota Calendar, Proton Calendar has a more polished interface, better mobile apps, and deeper integration with email workflows. Users often find Proton easier to adopt while maintaining comparable security standards.

Cons

Competitor

Cons
Google Calendar Compared to Google Calendar, Proton Calendar lacks advanced smart features like AI scheduling suggestions, automatic event parsing at scale, and deep third-party integrations, which can reduce productivity for power users.
Microsoft Outlook Calendar Outlook Calendar offers stronger enterprise collaboration tools, shared resources, and meeting room management. Proton Calendar is more limited for large teams and does not yet match Outlook’s depth in corporate scheduling.
Apple Calendar Apple Calendar integrates more tightly with device-level features like Siri and offline access. Proton Calendar currently depends more on connectivity and lacks the same level of native OS automation.
Zoho Calendar Zoho Calendar provides richer business tools such as resource booking and CRM-linked scheduling. Proton Calendar prioritizes privacy over business automation, which may feel restrictive for organizations.
Tutanota Calendar Tutanota Calendar can feel more lightweight, but it offers simpler offline handling in some scenarios. Proton Calendar users sometimes report limited offline functionality, especially for on-the-go use.

Verified Customer Reviews

  • androidauthority.com Review: The switch from Google Calendar felt limiting, even though the sign-up process stayed straightforward and allowed account creation directly inside the app without jumping to the web. An automatically added “Holidays” calendar and the appeal of a fully independent platform attracted interest, yet key gaps compared to Google Calendar left the overall experience feeling like a mistake.
  • Reddit r/ProtonMail: One commenter called it “bare-bone” and unsuitable as an on-the-go tool because it doesn’t work offline and forces every task to exist as a time-blocked or all-day event due to the lack of a to-do feature. Another criticized weak calendar sharing notifications, where custom alerts revert to default notifications for others, though someone else praised Proton overall and liked the Android widget’s look.
  • apple.com Review: The app feels functional and free of glaring bugs, and one reviewer values the security focus with minimal AI/LLM integration after leaving Google Suite. Missing conveniences frustrate users, including no auto address lookup in the location field, no in-app way to subscribe to calendars, limited search for past events, and no customizable notification sounds or haptics.
  • devproblems.com Review: The web interface earns praise for its clean, fast, and feature-rich design, and reliable in-app and email reminders build trust. A macOS workaround that uses a shareable link and PWA setup delivers notifications in the native Calendar app, yet it only grants read-only access and requires server-side decryption, which weakens the end-to-end encryption that makes Proton Calendar appealing.
  • bysolopreneurs.com Review: Proton Calendar appeals to privacy-first users with zero-access encryption for event content and tight integration with Proton Mail, Drive, VPN, and Pass under one bundle. The lack of CalDAV or Exchange support, no advanced resource booking, and fewer third-party integrations create friction for teams that rely on Outlook or Google Workspace, so the choice comes down to security versus AI scheduling and enterprise tooling.