Honest comparison

OneCal vs Caltsu.
Which one fits you?

Both tools are great for syncing calendars across Google, Outlook, and Apple. The best one for you comes down to a few key differences in privacy, pricing, and features. Let's break it down.

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
€7/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

Your calendars update the moment a change is made. No waiting for the next polling cycle. It's genuinely real-time.

Free tier & lower price

Start with up to 3 calendars for free, forever. Pro is €7/month (billed annually). 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 is built for individual professionals who need a simple, powerful sync tool that just works.

Try Caltsu free.

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