Sync your calendars.
Simple. Secure. Automatic.
Kalender Sync connects Outlook, iCloud, Google & kSuite in real time – one- or two-way, and you decide per sync what's visible: busy only, title + time or full details. Never double-book again, plus live-sharing into other calendars – 100% GDPR-compliant from Germany, from just €4/month.
Currently supported providers
Connect calendars
Sign up and connect your calendars in a few clicks – using the familiar Google, Microsoft or Apple login.
Choose visibility & sync
You decide: one-way or two-way sync, who sees what, and whether to share your calendar with someone else.
Automatically in sync
From now on it runs in the background. Blocked slots appear by themselves – never worry about double bookings again.
One-way or two-way sync
Sync in one direction or both: per connection, decide whether a calendar is mirrored one-way or both calendars keep each other in sync (bidirectional).
GDPR-compliant & hosted in Germany
Built in Munich, made for Europe. Your data is processed in line with GDPR and hosted on servers in Germany.
For yourself or to share
Sync several of your own calendars with each other – or create a sharing for someone else. They get invited, add it to their calendar, and from then on everything stays in sync.
You decide what's visible
Per sync, pick whether only "busy" or full event details transfer. You can even set the label a blocked slot appears under – e.g. your own custom label.
Use cases
For everyone who needs to stay on top of their schedule
From tax advisors and teachers to executives: anyone juggling many appointments across multiple calendars saves time and stress with Kalender Sync.
Wall of Love
Don't just take our word for it.
Our users are our best and most honest ambassadors. See why they wouldn't go back.
„When you run several companies you eventually lose track of which calendar holds what. KalSync has been humming in the background for months – set it up once and never double-book again. That's how it should be."
„I'm on a job site, not at a computer. When a customer calls I need to know in a glance whether I have time – now I do. Customer appointments, supply runs, family – all in one calendar."
„As a dev with a day job and side projects I kept getting collisions between work and freelance. KalSync separates them cleanly now – my employer only sees 'busy', my clients see their slots. Exactly how it should be."
„What really bugged me: colleagues could see the titles of my private appointments when I blocked time. Now it just says 'busy' – sounds small, but it makes a real difference."
„I'll be honest, I'm not a tech person. But juggling lectures, office hours and management meetings in separate calendars was a nightmare. Set it up once, it runs – that's all I need."
„Between agency work, my own projects and client meetings things get messy fast. KalSync keeps it all in sync without me lifting a finger – I see in a glance when I'm actually free. De-stressed my calendar."
About us
Why we built Kalender Sync
We, Paul Koch and Julius Hasenzahl, are both founders running multiple companies — which means we juggle a thousand calendars too. We know the double-booking pain. What we were missing: a solution that's truly GDPR-compliant, made in Europe and leaves us in control — one- or two-way, with selectable visibility. So we built one ourselves.
Happy to help if you have questions or ideas for getting your sync setup even sharper.
Clicking play loads YouTube. Data will be sent to Google.
Ready to fix your calendar chaos for good?
Try free for 14 daysCurrently supported providers
Google Microsoft Apple iCloud KSuite iCal-FeedsNewsletter
Join the Kalender Sync community
Subscribe to our newsletter and get early access to the hottest beta features — so your setup keeps getting better.
Promise: no spam, no AI-generated filler.
