Compare software

Zoho CalendarProton Calendar
Freemium

Free to start, with paid Zoho plans for business features.

 Freemium

Free account available, with paid Proton plans and a business version.

Web Android, iOS, Web
  • Team calendars with availability checks
  • Built-in appointment and resource booking
  • End-to-end encryption of event details
  • Built-in scheduling for booking meetings
  • Hosted service, with data stored by Zoho
  • Most useful inside the wider Zoho ecosystem
  • Requires a Proton account
  • Works best within the Proton ecosystem
Web application Downloadable app, Web application, Hosted service
Closed source Closed source
License not stated License not stated
Account needed Account needed
Not stated if it works offline Not stated if it works offline

Checked October 2, 2026

Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.