Proton Calendar
An app that keeps your calendar encrypted end to end.
What Proton Calendar does
Proton Calendar is a privacy-first calendar from Proton, the company behind Proton Mail. Event titles, descriptions and participants are end-to-end encrypted, so not even Proton can read them. It's free with a Proton account and works on the web, iPhone and Android.
Many calendar apps can read everything you put in them. Proton Calendar is built so it can't. Your event names, descriptions and guest lists are end-to-end encrypted, and only you and the people you share with can read them.
It covers the everyday basics: day and agenda views, notifications before events, and home screen widgets that show what's coming up. If you use Proton Mail, invitations that land in your inbox go straight onto your calendar, and you can reply to them from the app.
Sharing works best when everyone is on Proton. You can share calendars with other Proton accounts and edit events in calendars shared with you. You can also subscribe to outside calendars by link, but those stay read-only and refresh on a delay, so it isn't a full replacement for live two-way Google sync.
Pick it if privacy is the reason you're switching. If your family or team lives in Google Calendar, expect a bit of friction.
Alternatives to Proton Calendar
Who it's for
Skip it if: Families or teams who rely on Google Calendar sharing. Anyone who wants lots of planner extras like tasks or habits.
Pricing
Free planProton Calendar is free with a Proton account, and the free plan includes up to 3 personal calendars. Paid Proton plans, like Mail Plus, raise that to 25 calendars and add more across Proton apps. We couldn't confirm US prices, so check Proton's pricing page before you upgrade.
Prices can vary by country. Checked 19 Oct 2026.
What people like
- Strong privacy with end-to-end encryption
- Works on the web, iPhone and Android
- Free to start with a Proton account
- Tight fit with Proton Mail invites
Watch out for
- Sharing is smoothest only with other Proton accounts
- Outside calendars are read-only and update slowly
- Fewer features than big-name calendar apps
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Questions people ask
Is Proton Calendar free?
Yes. You can use it free with a Proton account, with up to 3 personal calendars. Paid Proton plans raise that to 25.
Is Proton Calendar end-to-end encrypted?
Yes. Event titles, descriptions and participants are end-to-end encrypted, so Proton can't read them.
Can I share Proton Calendar with my family?
Yes, with family members who have Proton accounts. They can view or edit events in the calendar you share.
Does Proton Calendar sync with Google Calendar?
Not live. You can import or subscribe to a Google calendar by link, but subscribed calendars are read-only and update on a delay.