Proton Calendar

Proton Calendar is a privacy-focused calendar for personal scheduling, invitations, and shared planning. It fits Proton Mail users and anyone who wants event details encrypted, while readers needing broad two-way synchronization or generous free sharing should consider other services. Its strongest case is keeping calendar content private without giving up appointment and meeting tools.

Overview

Proton Calendar handles creating, editing, deleting, and organizing recurring events and invitations. Notifications arrive through desktop browsers or mobile devices, so it covers routine personal and work scheduling across supported devices. End-to-end or zero-knowledge encryption protects event titles, descriptions, locations, and invited people, not merely the calendar account itself.

Proton AG is incorporated and headquartered in Plan-les-Ouates, Geneva, Switzerland, and follows Swiss privacy laws. Direct Proton Mail integration lets users send invitations and add events from their inbox. That makes the service particularly coherent for people already using Proton’s mail ecosystem, though users outside it may find fewer reasons to switch.

Key features

Appointment scheduling automatically updates availability and adds confirmed meetings. For people arranging appointments, that removes repetitive calendar maintenance. Scheduling links support booking, and video meeting support is included. Event notifications work in desktop browsers and on mobile devices.

Users can share scheduling links, while paid plans add calendar sharing by link with other calendar services on the web. Import and export are also paid features. Calendar sync is one-way, so Proton Calendar suits workflows where Proton is the destination rather than a hub requiring changes to travel back and forth between services.

Mail integration is a practical advantage: invitations can be sent and events added directly from Proton Mail. Event management includes recurring meetings and invitations, giving the service enough depth for regular household, freelance, and business calendars. Proton says more than 100,000 business users trust Proton Calendar, but the product remains centered on privacy and Proton account integration rather than a broad collaboration suite.

Pricing

Free

The Free plan costs nothing, billed monthly, and provides essential Proton Calendar features with a free Proton account. Its hard limit is three calendars. It is a sensible starting point for one person managing a small number of calendars, but it does not include paid-plan sharing by link or import and export.

Mail Plus

Mail Plus has custom pricing and supports one user with up to 25 calendars. It is the practical step up for a Proton Mail subscriber who needs more calendar capacity, web sharing links, and import/export without requiring a multi-user arrangement.

Unlimited

Unlimited also has custom pricing, supports one user, and allows up to 25 calendars. It suits a subscriber who wants Proton’s broader paid offering while retaining the additional calendar features, rather than someone seeking extra seats.

Paid

Paid Proton Mail subscribers receive additional calendar features, with custom pricing. Subscriptions bought through proton.me renew automatically. Plans can be changed at any time, and upgrades receive prorated credit, which reduces the cost of moving up mid-term but makes renewal settings worth checking.

Platforms

Mobile apps are available for Android and iOS. Desktop-browser notifications extend access beyond the mobile apps. Proton Calendar supports one-way synchronization; readers requiring two-way changes between calendars should look elsewhere.

Who it's for

Choose Proton Calendar if encrypted titles, descriptions, locations, and attendee information matter, especially when you already use Proton Mail. The free tier works for a lightweight personal setup within three calendars. Paid Proton Mail users are better served when they need up to 25 calendars, sharing links, or import and export.

It is less suitable for teams that need multiple user seats in these plans, or for anyone whose workflow depends on bidirectional calendar synchronization. Users seeking a family-first calendar, open-source desktop suite, or broader workplace platform may find a closer fit among the alternatives.

Pros and cons

Pros

• Encrypted event content: Titles, descriptions, locations, and invitees receive end-to-end or zero-knowledge protection.
• Strong Proton Mail connection: Invitations and event creation can happen directly from Proton Mail.
• Useful scheduling tools: Availability updates, confirmed-meeting additions, scheduling links, recurring events, and video meeting support cover more than basic date keeping.
• Swiss legal jurisdiction: Proton operates from Switzerland and follows Swiss privacy laws.

Cons

• Free plan ceiling: Three calendars can be restrictive for users separating work, personal, family, and projects.
• Paid gate for portability and sharing: Calendar sharing by link and import/export require a paid plan.
• One-way synchronization: Changes do not sync in both directions, limiting mixed-calendar workflows.
• Single-user paid plans: Mail Plus and Unlimited list one user, so they are not presented as multi-seat team plans.

Alternatives

• Mozilla Thunderbird is the better choice for a free, open-source desktop suite combining email, calendar, and contacts across Android, Linux, macOS, and Windows.
• Microsoft Outlook Calendar fits readers wanting a mainstream freemium calendar across Android, iOS, macOS, and the web, with a one-month Microsoft 365 trial.
• Tuta Calendar is an alternative privacy-oriented freemium calendar with a free one-calendar tier and broader platform coverage.
• Lark is worth considering when calendars belong inside a wider team workspace with users, storage, message history, and automations.
• EGroupware suits organizations seeking an open-source web groupware option with a free trial and an eCloud NGO plan.
• Zoho Calendar provides a free online calendar for individuals and teams, including one appointment-booking link for free users.
• Teamup is aimed at shared scheduling with sub-calendars, users, custom fields, and historical data in its free plan.
• Cozi is the more family-oriented option, combining a shared calendar with grocery and to-do lists, notifications, and recipes.
• Calendar apps offers a wider set of services to compare.

Verdict

Proton Calendar is the right pick for privacy-conscious individuals and Proton Mail users who want encrypted event details, integrated invitations, and capable appointment scheduling. Choose it for that privacy-and-ecosystem combination; look elsewhere if three free calendars, paid-only sharing, or one-way sync conflict with how you organize calendars.