End-to-end encrypted calendar. Event titles, descriptions, locations, and attendees are all encrypted. Part of the Proton ecosystem — easiest switch if you already use Proton Mail. Significant limitations compared to Google Calendar.
If you have a Proton Mail account, Proton Calendar is already included — go to calendar.proton.me and log in. If not, create a free account at proton.me. Proton Calendar encrypts all event data client-side: titles, descriptions, locations, and attendees are encrypted before they reach Proton's servers. The free plan supports up to 3 calendars.
The Proton Calendar web interface showing an empty calendar in week or month view. A default "My calendar" appears in the sidebar.
Go to calendar.google.com, click the gear icon, then Settings. In the left sidebar, click "Import & export", then "Export". Google will download a .zip file containing .ics files — one per calendar. Unzip the file. If you have multiple Google calendars (personal, work, birthdays), each will be a separate .ics file. Review which ones you want to migrate.
One or more .ics files on your computer. Open one in a text editor to confirm it contains your events (you will see VEVENT entries with your event titles).
In Proton Calendar, click the gear icon, then "Import". Select your .ics file and choose which Proton calendar to import into. If you want to keep calendars separate, create new calendars first (Settings → Calendars → "Create calendar"). Proton imports events, dates, times, descriptions, and locations. Recurring events import correctly. The import limit is 15,000 events per calendar.
Your events appear in Proton Calendar. Check a few upcoming events to confirm titles, dates, times, and recurrence patterns are correct.
Download Proton Calendar from the App Store (iPhone) or Google Play Store (Android). Log in with your Proton account. On Android, the calendar integrates with the system calendar if you enable it in settings — your Proton events appear alongside other calendar apps. On iPhone, Proton Calendar is a standalone app. Enable notifications in the app settings so you receive event reminders.
Your imported events visible on your phone. Create a test event and confirm it syncs to the web version within a few seconds.
Proton Calendar has real limitations compared to Google Calendar. No calendar sharing with non-Proton users without losing encryption. No file attachments on events. No offline access on mobile. No scheduling links (like Calendly integration). No third-party app integrations via CalDAV. These are trade-offs of end-to-end encryption — the server cannot process what it cannot read. For shared family or work calendars, you may need to keep Google Calendar for those specific use cases.
You understand which features you use in Google Calendar that Proton does not support, and have a plan for how to handle those cases.