Introducing freigabe.dev - Calendar Sync, Done Right

The Problem: Calendars Don't Talk to Each Other

If you use both Google Calendar and Microsoft Outlook - whether for personal and work accounts, or across multiple organizations - you know the pain. Double bookings. Missed availability. Manually blocking time in one calendar because the other one doesn't know you're busy.

Existing solutions either cost over 10 EUR per user per month, bundle calendar sync with AI scheduling features you don't need, or require handing over full read access to every event on your calendar.

What Is freigabe.dev?

freigabe.dev is a SaaS that syncs calendars bidirectionally across Google Workspace and Microsoft 365. The name comes from the German word Freigabe, meaning both "release" (as in software) and "clearance to proceed" - fitting for a tool that keeps your availability clear across platforms.

The core idea is simple: connect your calendars, and freigabe.dev automatically creates availability blockers across all of them. When you have a meeting in your Google Calendar, your Outlook calendar shows you as busy - and vice versa. No manual effort, no missed conflicts.

Privacy by Design

freigabe.dev takes a deliberate approach to privacy. By default, synced events appear as simple availability blockers - showing only the time slot and which source calendar it came from (e.g. "Blocked (Acme Corp Outlook)"). No event titles, no attendee lists, no descriptions are shared across calendars unless you explicitly choose full-detail sync.

Authentication and calendar access are decoupled: signing in requires only basic profile information, while calendar permissions are requested separately and only in context. Revoking calendar access does not log you out, and vice versa.

Built at SAILBAHN.dev

freigabe.dev is built and operated by SAILBAHN.dev. The stack runs on Next.js with Supabase for the database layer, deployed on Google Cloud Run in Europe. Sync is driven by a custom job queue built on plain Postgres - no external queue service, no vendor lock-in. Webhooks from Google and Microsoft trigger near-instant sync, with a polling safety net to catch anything that slips through.

We built this because we needed it ourselves. Managing calendars across client organizations, personal accounts, and internal scheduling was a daily friction point - and the tools on the market were either too expensive or too bloated for what is fundamentally a straightforward problem.

Beta: What to Expect

freigabe.dev is now in beta. The core sync engine is stable and has been running in production for our internal use. During the beta period:

• Google Calendar sync is fully operational - connect multiple Google accounts and select which calendars to include in your sync group.
• Microsoft 365 / Outlooksync works, but currently requires admin consent from your organization's IT administrator. We are working on completing Microsoft's publisher verification process to enable self-service access.
• Access is by invitation during the beta. If you are interested in trying it out, reach out to us or sign up through the landing page.

What's Next

After the beta stabilizes, we are planning to add billing integration, full-detail sync mode for users who want complete event copies across calendars, and CalDAV support to bring Apple iCloud, Fastmail, Nextcloud, and other self-hosted calendars into the mix.

If cross-platform calendar sync is a pain point for you or your team, visit freigabe.dev to learn more or get in touch with us directly.