Sync your calendars.
Simple. Secure. Automatic.
Sync Google, Outlook and iCloud automatically via Free/Busy — no new app, no manual updates, 100% GDPR-compliant.
Get started for free
Find the right setup in 3 steps.
Step 1 of 3
What would you like to do?
Step 2 of 3
Which calendars do you use?
Multiple selection possible
Step 3 of 3
We're working on it!
Your provider isn't supported yet, but we're working on it.
How it works
Clean availability in three steps.
Connect calendars
Sign up and connect your calendars in a few clicks.
Choose visibility
Decide who can see which availability. You stay in full control.
Automatically synced
Kalender Sync keeps your availability up to date in the background. Blocked slots appear automatically.
Why Kalender Sync
Your events stay private. Your availability doesn't.
Other tools copy your events completely — with titles, attendees and notes. Kalender Sync only transfers whether a slot is free or busy. Nothing more.
Free/Busy only — no event details
The target calendar shows "Blocked." No title, no attendees, no notes. Not even visible to admins.
Hosted in Germany
Servers at Hetzner in Nuremberg. No US cloud, no third-country transfers. DPA available.
5 providers, one background service
Google, Outlook, iCloud, KSuite, iCal feeds. Connect once, runs automatically. No new app, no tab to keep open.
Real-time via webhooks
Changes sync instantly — not every 24 hours like iCal feeds. New meeting in Outlook? Blocked in Google within seconds.
"I built Kalender Sync because no tool on the market could sync availability without copying event details. For European teams, that's not an option."
Paul Koch
Founder, Kalender Sync
13,000+
Events synced
< 5 min
Setup time
100%
GDPR-compliant
Frequently asked questions
Transparent answers for teams that want to keep work and personal calendars separate.
What exactly does Kalender Sync synchronize?
Kalender Sync syncs free/busy information between your existing Outlook, Google and iCloud calendars. KSuite and iCal feeds are also supported. Content like titles or notes stays confidential.
Do I need a new app or another tool?
No. You connect your calendars once and keep working in your familiar apps. The sync runs as a background service and keeps your slots up to date.
Which calendars are supported?
Google Calendar, Microsoft Outlook / Office 365, Apple iCloud, KSuite (Infomaniak) and any iCal feeds. More CalDAV providers are coming soon.
How do you handle data protection and GDPR?
We host in Germany, process only availability data, and provide a data processing agreement. Kalender Sync uses least-privilege access.
Ready to get started?
Connect your calendars in minutes.
Step 1 of 3
What would you like to do?
Step 2 of 3
Which calendars do you use?
Multiple selection possible
Step 3 of 3
We're working on it!
Your provider isn't supported yet, but we're working on it.