CalDAVconnect vs. Kalender Sync: CalDAV Bridge or All-Round Sync?
Comparison at a glance
| Feature | CalDAVconnect | Kalender Sync |
|---|---|---|
| Focus | CalDAV server ↔ Google Calendar or Microsoft 365 | Calendar providers with each other (e.g. Outlook ↔ Google) and sharing with other people |
| Own CalDAV servers (Nextcloud, SOGo, Radicale, Baïkal, Synology) | Yes, all five tested | No; Nextcloud listed as “coming soon” |
| Cloud calendars | Google Calendar, Microsoft 365, Outlook.com | Google, Outlook/Microsoft 365, Apple iCloud |
| Calendars from email providers | Posteo, mailbox.org, Infomaniak (tested) | GMX, WEB.DE, mailbox.org, Posteo, Infomaniak kSuite; plus iCal feeds as import |
| Google ↔ Microsoft directly | No, one side is always a CalDAV calendar | Yes |
| Sync speed | Cloud → CalDAV 1–2 seconds (webhooks), CalDAV → cloud 7–8 seconds on average; hourly on the Free plan | “Real time (webhook)” from Basic; 30 minutes on the Free plan |
| Direction | Bidirectional or one-way, per calendar pair | One-way or two-way, per sync |
| Visibility | Per calendar pair: full details, “Busy” or your own label with organizer, or Strict (time block only) | Per sync: busy only, title + time, or full details; custom label from Basic |
| Time range | Default: last 90 days (adjustable up to unlimited) and all future events | 3 months back; 6 months ahead (Free, Basic) or 18 months (Professional, Team) |
| Share calendars with other people | No | Yes, live sharing by invitation |
| AI assistant | No | Yes, its own MCP server |
| Free plan | 1 connection, hourly sync, syncs your own calendars | 2 calendar accounts, 1 sharing; syncing your own calendars from Basic |
| Paid plans | Solo €2/month (1 connection); Pro from €5/month (5 connections, €1 per additional one); Team from €10/month as a pilot on request | Basic €5/month (3 accounts, 5 syncs); Professional €12/month (unlimited); Team individually priced from 5 users |
| Trial | 14 days of the full version, no credit card | 7 days of Professional, no credit card |
| Hosting | Hetzner, Germany | Hetzner, Germany |
| Data processing agreement (DPA) | On every plan including Free, in effect from sign-up | From Basic on request, not on the Free plan |
| Teams and organizations | Members and roles, change log; admin controls and single sign-on with Google Workspace in pilot | Central administration, policies, audit log; single sign-on with Entra ID and Google Workspace on request |
Information about Kalender Sync as published on its website, as of October 9, 2026: kalender-sync.de, kalender-sync.de/preise
CalDAVconnect and Kalender Sync are both German services, both host at Hetzner in Germany, and both keep calendars up to date automatically. They solve different problems, though. This page shows where they differ, so you can quickly see which tool fits your setup.
The short answer
CalDAVconnect is the bridge between a CalDAV server and Google Calendar or Microsoft 365. If your events live in Nextcloud, SOGo, Radicale, BaĂŻkal, on a Synology or with Posteo, mailbox.org or Infomaniak, and you need them in Google or Outlook, that is exactly our use case.
Kalender Sync connects calendar providers with each other: Outlook with Google, iCloud with Outlook, GMX with Google and so on. It also lets you share your availability into other people's calendars. If you don't run your own server and use iCloud, GMX or WEB.DE, it is the better fit.
Supported calendars
With CalDAVconnect, one side of a connection is always a CalDAV calendar and the other is Google Calendar or Microsoft 365. Tested servers are Nextcloud, SOGo, Radicale, BaĂŻkal, Synology, Posteo, mailbox.org and Infomaniak. Other servers that speak standard CalDAV usually work too. A connection covers every calendar on the server: you create one pair per calendar and decide which calendar syncs where.
According to its website, Kalender Sync covers more providers: Google, Outlook/Microsoft 365, Apple iCloud, GMX, WEB.DE, mailbox.org, Posteo, Infomaniak kSuite and iCal feeds. Self-hosted CalDAV servers such as Nextcloud are not supported yet; Nextcloud is announced as “coming soon”. mailbox.org, Posteo and Infomaniak are supported by both services.
Sync speed
CalDAVconnect uses two mechanisms. Google Calendar and Microsoft 365 report changes via webhooks; they reach your CalDAV server within 1–2 seconds. The other direction has no webhook equivalent, because CalDAV servers such as Nextcloud or SOGo don't notify external services of changes. CalDAVconnect therefore checks every 15 seconds, with a single lightweight request, whether a calendar has changed (CTag). On average a change appears in the cloud after 7–8 seconds. The details are in How CalDAVconnect syncs in seconds.
Kalender Sync states “real time (webhook)” from its Basic plan and 30 minutes on its Free plan. With CalDAVconnect, the Free plan syncs hourly, Solo and Pro within seconds.
Data protection and visibility
Both services host in Germany and offer a data processing agreement. CalDAVconnect's DPA applies to every plan including Free, from sign-up. According to its pricing page, Kalender Sync offers one from Basic on request.
CalDAVconnect encrypts credentials and the stored state of every event with AES-256-GCM; the keys live on a separate server. What we store and for how long is described on Security & data protection for IT teams.
With both services you control how much of an event reaches the other side. With CalDAVconnect you choose a privacy mode per calendar pair: full details, “Busy” or your own label with the organizer visible, or Strict, which transfers only the time block. Kalender Sync offers “busy only”, “title + time” or full details per sync, and a custom label from Basic.
Pricing
| CalDAVconnect | Kalender Sync | |
|---|---|---|
| Free | 1 connection, hourly | 2 accounts, 1 sharing |
| Entry plan that syncs your own calendars | Solo, €2/month | Basic, €5/month |
| Several calendars | Pro from €5/month, €1 per additional connection | Professional, €12/month |
A CalDAVconnect connection is one CalDAV server with one cloud account, including every calendar on that server. Kalender Sync counts calendar accounts and syncs. Current prices are on our pricing page.
Corrections
The Kalender Sync comparison page states two things about CalDAVconnect that are no longer accurate (as of 9 October 2026):
- “CalDAVconnect mirrors calendars in full – per-connection control over the level of detail is not documented on its website.” CalDAVconnect offers privacy modes per calendar pair. They are described in the calendar pairs documentation and on the security page.
- “Pro from €5/month (5 connections) up to €11/month (15 connections)”. Pro no longer has fixed tiers: 5 connections for €5/month, €1/month for each additional one, up to 50 connections self-service.
Which tool fits?
CalDAVconnect fits if
- your calendars live on Nextcloud, SOGo, Radicale, BaĂŻkal, a Synology or with Posteo, mailbox.org or Infomaniak,
- you want to sync them with Google Calendar or Microsoft 365, in both directions and within seconds,
- you need a DPA even on the free plan.
Kalender Sync fits if
- you want to connect Apple iCloud, GMX or WEB.DE,
- you want to sync Google and Outlook with each other directly, without a CalDAV server,
- you want to share your availability live into other people's calendars or connect an AI assistant.
If your setup needs both, say a company Nextcloud and a private iCloud calendar, the two services don't exclude each other.
Frequently asked questions
According to kalender-sync.de, Nextcloud is “coming soon” there (as of 9 October 2026). CalDAVconnect already syncs Nextcloud bidirectionally with Google Calendar and Microsoft 365, as well as SOGo, Radicale, Baïkal and Synology.
Kalender Sync connects Apple iCloud, GMX and WEB.DE directly. CalDAVconnect has not tested these providers and is not the first choice for them.
Yes. With CalDAVconnect you choose a privacy mode per calendar pair: full details, “Busy” (or your own label) with the organizer visible, or Strict with the time block only. Kalender Sync offers “busy only”, “title + time” or full details per sync.
CalDAVconnect’s Free plan syncs one connection hourly; sync within seconds starts with Solo at €2/month. With Kalender Sync, syncing your own calendars starts with Basic at €5/month; its Free plan includes one sharing with another person.