Tool comparison
Kalender Sync vs. OneCal – which sync fits you?
OneCal is a mature sync tool with booking links and mobile apps – but runs on AWS. Kalender Sync focuses on pure sync, hosting in Germany and Free/Busy by default. Here's the honest comparison.
Background
What is OneCal?
OneCal is an international sync tool that connects Google Calendar, Microsoft Outlook and Apple iCloud in real time. Multi-way sync, booking links, a unified calendar view and native iOS/Android apps are part of the feature set. Privacy is controlled via configurable visibility rules – e.g. transferring only "busy" instead of event content. The platform runs on AWS, with security features like private VPC, encryption in transit and at rest, and regular vulnerability scans.
Strengths
Where OneCal is strong
Polished UX and mobile apps
OneCal has a polished interface, integrated unified calendar view and native iOS/Android apps. If you want sync, booking links and calendar management in one app, this is it.
Granular visibility control
Per sync, you can decide whether title, description, location and attendees are transferred – or only "busy". Very fine-grained tuning is possible.
Booking links included
Customisable scheduling links with branding, buffers and reminders – usable as a Calendly replacement.
Where Kalender Sync wins
Where Kalender Sync wins
Hosting in Germany, not AWS
OneCal runs on AWS – even with EU-region servers, the US Cloud Act applies to the parent company. Kalender Sync hosts at Hetzner in Nuremberg, German company, German servers, no US cloud dependency.
Real calendar sharing – not just booking links
OneCal has scheduling links so others can book with you. What OneCal can't do: embed your calendar as a live feed inside someone else's calendar, kept automatically in sync there. That's a core feature of Kalender Sync.
One sync always free – no trial expiry
OneCal has a 14-day trial, then every plan costs money. At Kalender Sync, one synchronisation is permanently included in the Free plan – you never have to pay if you don't need more.
Free/Busy by default, not an option
At OneCal, you actively reduce visibility. At Kalender Sync, "busy only" is the default – event details only leave your calendar if you explicitly allow it. That matters for audits and works councils.
Provider breadth beyond the big three
OneCal supports Google, Outlook and iCloud. Kalender Sync additionally connects KSuite (Infomaniak, Swiss provider) and any iCal feeds – important for mixed EU setups.
Better price-to-value at entry
OneCal's Starter plan is $5 per user per month. Kalender Sync Basic is €4/month – and includes five calendar accounts and five syncs. Annual billing saves two months, effective rate ~€3.33/month.
DPA available
A data processing agreement is part of Kalender Sync's standard offering. For businesses with works councils, a clear advantage.
Decision guide
When to pick which
OneCal is the right choice when:
- You need a polished mobile app and unified view.
- US cloud hosting isn't critical for you.
- You want booking links out of the same tool.
Kalender Sync is the right choice when:
- You're in the EU/DACH and take privacy seriously.
- You serve regulated industries (tax, medical, education, legal).
- You also need KSuite, iCloud or iCal feeds.
- You want Free/Busy as the default – not an option someone could turn off.
Ready for calendar sync that passes the DACH compliance test?
Connect your calendars in a few clicks – GDPR-compliant and hosted in Germany.
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