Side by side
Calendar.online vs Proton Calendar
Both stand on calendar apps. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan AndroidAPIiPhone+1
Calendar.online combines shared calendars, booking links, reminders, and permission controls in one service. The free Basic plan covers smaller setups, while Plus and Premium expand calendar, link, booking, and history limits.
Visit Calendar.online
Free plan AndroidiPhone
Proton Calendar combines event management, scheduling features, and encrypted event details. The free plan has a 3-calendar limit; paid Proton Mail plans allow up to 25 calendars and add sharing and import/export features.
Visit Proton CalendarThe facts
| Calendar.online | Proton Calendar | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | Android, API, iPhone, Web | Android, iPhone |
| Lowest paid plan | Plus: $6.90 per calendar a month | Free or on request |
| Plans published | 3 | 4 |
| Maker | Calendar.online | Proton Calendar |
| Website | calendar.online | proton.me |
| On calendar apps | #26 of 194 | #30 of 194 |
Calendar.online: what it does well
- Free plan available forever
- Shared calendars with configurable link permissions
- Booking shows only available time slots
- iOS and Android apps
- Email and text appointment reminders
What to know first
- Basic limits sub-calendars and access links
- Calendar sync works one way
- Premium API requires Premium plan
- Paid plans billed monthly
Proton Calendar: what it does well
- Event details are protected with end-to-end or zero-knowledge encryption.
- Free accounts include up to 3 calendars.
- Scheduling links and video meeting support are listed.
- Events can be added directly from Proton Mail.
- Notifications are available on mobile devices and desktop browsers.
What to know first
- The free plan is limited to 3 calendars.
- Calendar sharing and import/export are listed for paid plans.
- Only Android and iOS platforms are listed.
- Subscriptions purchased through proton.me renew automatically.
Alternatives to Calendar.online Alternatives to Proton Calendar The whole list