SYNCDATE vs Kalender Sync: Sharing Your Availability or Controlling Your Sync

Quick Answer: Both tools host in Germany, both push Google and Outlook changes quickly, and both offer an MCP server and a DPA on every plan. The difference is what each one is built for. Kalender Sync is built around sharing: showing your availability inside another person's calendar. SYNCDATE is built around control over what your own calendars copy: skip all-day events or anything with a word you choose, copy only accepted invitations, sync only your working hours, write if/otherwise rules, and treat each calendar in a sync differently. Our free plan syncs two of your own calendars both ways, on any provider. Their free plan is one sharing into someone else's calendar.

Kalender Sync published a comparison against us, and we publish one back. Their figures below come from their own site and pricing page, read on 20 October 2026, and from corrections their team sent us in October.

Two tools that sound alike

On a feature checklist we look similar. Both connect Google, Outlook and iCloud. Both let a copy show as busy or with details. Both run two-way. If you only compare checkmarks, you will not find much between us.

The split shows up when your calendars stop being simple. A work calendar that shouldn't get your Saturday plans. A client calendar that should only see "Busy" while your own calendar keeps the real title, in the same sync. Invitations you haven't accepted, which shouldn't block time anywhere. A company-wide all-hands nobody wants copied three times. Those are settings questions, and settings are what SYNCDATE is made of.

What you can control on SYNCDATE

Which events cross at all. Every plan:

• Exclude events: skip all-day events, events whose title contains a word you choose, or events already marked as free time. Adding a rule also removes earlier copies it now matches.
• Which events to sync (RSVP): every invitation, only the ones you answered yes or maybe to, or only the ones you accepted.
• Days & hours to sync: copy only what falls inside the days and hours you pick. Saturday plans never reach the work calendar.
• Special event types: keep Google out-of-office, focus time, working location and contact birthdays out of the copy.

What each copy carries. Every plan: Busy, the original title, your own label, or a prefix. You can write the title, description and location yourself with pieces of the original dropped in, so a "Standup" from your Acme calendar arrives as "[Acme] Standup". You also choose colour, reminders and whether the description comes along. New syncs copy events as Busy. A two-way Mirror between calendars you own keeps the real titles. You can change either before you start.

Rules, on Plus and up. If/otherwise rules decide the result per event: if a meeting has 10 or more guests, mark the copy Busy; otherwise keep the original. Conditions can look at event length, start time, weekday, guest count or a guest's email domain, and results can use the meeting link, guests and organizer.

A different rule for each calendar, on Pro. Inside one sync, your own calendar keeps the real event while the client calendar it also syncs to shows "Busy". Title, privacy, guests, colour, description, location, reminders and free/busy can all differ per calendar.

Three or more calendars in one mirror, on paid plans: every calendar sees every other, as one sync.

Kalender Sync's site describes three visibility levels (busy only, title and time, or full details) and, from Basic, a custom label for blocked slots. Neither their site nor their pricing page lists event filters, RSVP filtering, working-hours windows, conditional rules, per-calendar settings, colour or reminders. If those exist, they are not published.

Providers: a protocol, not a list

Kalender Sync supports ten named provider types: Google, Outlook/M365, iCloud, GMX, WEB.DE, mailbox.org, Posteo, STRATO, Infomaniak kSuite and iCal feeds. On their free plan, Google and Outlook only.

SYNCDATE connects Google, Outlook and any standards-compliant CalDAV server, on every plan including Free. That covers iCloud, GMX, WEB.DE, mailbox.org, Posteo and Infomaniak, and also Fastmail, Nextcloud and self-hosted servers that aren't on anyone's list. iCal feeds work as a read-only source. If your provider speaks CalDAV, you don't wait for us to add it.

Google and Outlook changes usually reach the other calendar in under a minute; CalDAV calendars are checked about every 15 minutes; iCal feeds on a schedule.

The free plans do different jobs

Our free plan connects two calendar accounts from any provider and runs one sync between them, two-way. No card, no expiry. The settings above (filters, RSVP, working hours, custom text) come with it.

Their free plan includes one sharing: your availability shown in someone else's calendar. It does not include a sync between your own calendars; that starts on a paid plan. If you want your work and personal calendars to keep each other current without paying, ours does it and theirs doesn't.

Where Kalender Sync fits

You want someone else to see when you're busy. Their sharing flow invites another person and keeps your availability in their calendar. We sync calendars you connect yourself, so if the job is "let my manager see my busy blocks inside her own calendar", that's their product.

Your contract has to be with a German company. We're DUMA DIGITAL SOLUTIONS S.R.L., a Romanian company hosting at Hetzner in Germany and Finland, with a public DPA. If your works council or legal team names a German counterparty, they have one.

You want the lowest monthly price and the visibility levels plus a custom label are all the control you need. Compare their pricing with ours.

Where SYNCDATE fits

Your calendars need different treatment. A client calendar that only sees "Busy", a personal calendar that keeps the real title, invitations you haven't accepted kept out, weekends kept off the work calendar. Each of those is a setting here.

You want rules, not just a visibility level. If a meeting has 10 or more guests, mark the copy Busy; otherwise keep it. If a guest's email is from your client's domain, keep the title; otherwise show Busy. Rules come with Plus.

Your provider isn't on a list. Fastmail, Nextcloud, a self-hosted server: if it speaks CalDAV, it works, on the free plan too.

You want to sync your own calendars for free. Two accounts, one two-way sync, no card.

You want your assistant to manage the sync itself. Our MCP server lets an assistant manage your syncs on every plan, and read and change events on Plus, Pro and Team.

So which one?

If the person who needs to see your calendar is someone else, Kalender Sync is built for that. If you're the one who needs your calendars to behave, with control over which events cross, what each copy says and how each calendar is treated, that's SYNCDATE.

Privacy won't decide it. Both host in Germany, both are GDPR-compliant, both publish a DPA on every plan.