Honest comparison

OneCal vs Caltsu.
Which one fits you?

Both tools sync calendars across Google, Outlook, and Apple. The real differences are in privacy, pricing, and where your data lives. Here's an honest look.

Feature
Caltsu
OneCal
Real-time sync (webhooks)
Google Calendar
Outlook / Microsoft 365
Apple Calendar
Bi-directional sync
EU-hosted / GDPR-first
Event data stored on servers
No — metadata only
Yes
Free tier
Yes
No
Pro pricing
€8/mo
~$8.30/mo (annual)
Calendars on free tier
Up to 3
Calendars on Pro tier
Unlimited
Unlimited
Booking links
Team / org features

Where Caltsu wins.

Privacy by design

Caltsu never stores event titles or descriptions on its servers. We sync availability, not your data. OneCal processes event data through US-based servers.

EU-hosted, GDPR-first

All Caltsu infrastructure runs in the EU. For European professionals and companies with data residency requirements, this matters.

Webhook-first architecture

Changes propagate the moment a calendar event is created or modified. No background polling intervals. Truly real-time.

Free tier & lower price

Start with up to 3 calendars for free, forever. Pro is €8/month. OneCal has no free plan and starts at ~$8.30/mo when billed annually.

Where OneCal wins.

Bigger ecosystem

OneCal has been around longer and integrates with more third-party tools and platforms beyond core calendar sync.

Booking links

OneCal bundles scheduling/booking link features. If you need Calendly-style links alongside sync, OneCal has you covered.

Team features

OneCal offers team plans with shared calendars and org-level management. Caltsu currently focuses on individual professionals.

Try Caltsu free.

14-day Pro trial, no credit card required. Connect your calendars in under two minutes and see the difference.