Calendar sync tool comparison

The best calendar sync tools 2026 – an honest comparison

OneCal, CalendarBridge, SyncGene, Reclaim.ai or Kalender Sync? We compare the most important providers honestly by features, price, privacy and hosting – so you find the right tool for your setup and use case.

Try free for 30 days Comparison table

Intro

What matters in the comparison

Anyone using multiple calendars knows the problem: Google, Outlook and iCloud don't talk to each other. One double-booking later, you're asking "which sync tool should I pick?". The honest answer: it depends on what matters more to you – maximum feature set, lowest price or uncompromising European privacy.

Six factors decide:

Privacy & hosting – Where is your event data processed? Tools with US servers fall under US law (Cloud Act, FISA 702), even if they claim GDPR compliance.
Supported providers – Google, Outlook, iCloud are standard. Niche providers like KSuite (Infomaniak), CalDAV or arbitrary iCal feeds are only found in a few tools.
Sync mode & visibility – Copy "full details" or only show "busy"? This default reveals a lot about a tool's privacy philosophy.
Sync direction – One-way or both, selectable per connection?
Speed – Real-time (webhooks/push) or periodic polling (every 10–15 minutes)?
Price & limits – How many calendars per plan? How does it scale for teams?

Comparison table

At a glance

As of May 2026. Please verify pricing and features on the vendors' websites before purchasing.

Criterion	Kalender Sync	OneCal	CalendarBridge	SyncGene	Reclaim.ai
Vendor & location
Headquarters	Munich, DE	EU (AWS)	Chicago/Miami, US	(Azure-hosted)	US
Hosting	Germany (Hetzner)	AWS	US cloud	Microsoft Azure	US cloud
GDPR DPA	Available	On request	Available	Available	Available
Privacy
Default visibility	"Busy" only (Free/Busy)	Configurable	Full details	Full details	Per-sync choice
Functionality
Supported providers	Google, Outlook, iCloud, KSuite, iCal	Google, Outlook, iCloud	Google, Outlook, iCloud, ICS	Google, Outlook, iCloud, more	Primarily Google, Outlook
Sync speed	Real-time	Real-time (iCloud up to 10 min)	Real-time	Periodic	Real-time
One-way / two-way	Both, per connection	Both	Both	Both	Both
Booking links	—	Included	Included	Included	Included (AI-powered)
Share calendar (embed in someone else's)	Yes (Free: 1, Basic: 5, Business: ∞)	—	ICS feeds only (no live sync)	—	—
Self-sync (multiple own calendars)	Yes	Yes	Yes	Yes	Partial
AI assistant	—	—	Yes (Premium/Pro)	—	Yes (core feature)
Pricing
1 sync always free	Yes, permanently	14-day trial	Trial	Limited on Free	Free plan limited
Entry price	Free / €4	$5 / user / month	$4 / month (2 cals)	Free / paid	Free / $10
Entry value	5 accounts for €4	1 user for $5	2 calendars for $4	Limited	1 sync free

The five tools at a glance

Which tool was built for what

Kalender Sync

The specialist for GDPR-compliant sync

Our tool

Hosting in Germany (Hetzner, Nuremberg), DPA available, Free/Busy by default.
Supports Google, Outlook, iCloud, KSuite (Infomaniak) and any iCal feeds.
Only tool in the comparison with true live calendar sharing into other calendars.
One sync permanently included in the Free plan. Basic with 5 accounts for €4/month.
Intentionally no AI assistant, no unified view, no task planning – just clean sync.

For who: Tax advisors, coaches, schools, executives across multiple companies, AI agent integration with privacy needs.

OneCal

The all-rounder

Clean UX, multi-way sync, granular visibility control, native mobile apps.
AWS hosting – no EU hosting guarantee. iCloud sync up to 10-minute latency.

For who: International freelancers and consultants for whom US cloud hosting is uncritical.

Detailed comparison: Kalender Sync vs. OneCal

CalendarBridge

The veteran with AI integration

On the market since 2019, own patent on privacy-focused sync method, AI assistant included.
Headquartered in the US (Chicago/Miami), data subject to US law. Full event details are the default.

For who: US-oriented consultants wanting AI-assisted scheduling in their workflow.

Detailed comparison: Kalender Sync vs. CalendarBridge

SyncGene

The multi-sync generalist

Beyond calendars, also syncs contacts and tasks, SOC 2-certified, runs on Microsoft Azure.
Azure hosting (US vendor), sync periodic instead of real-time, broad complexity. Transitioning to brand CiraHub.

For who: Individuals wanting to consolidate contacts and events across multiple devices.

Detailed comparison: Kalender Sync vs. SyncGene

Reclaim.ai

The AI planning assistant

Best AI planning on the market, priority-based scheduling, generous free plan, true two-way sync between Google and Outlook.
Calendar sync isn't the core feature, iCloud isn't supported directly (only via Google detour). US vendor.

For who: Solo pros and small teams wanting to integrate time-blocking and habits into their workflow.

Detailed comparison: Kalender Sync vs. Reclaim.ai

Recommendation

Which tool fits whom?

You want sync as a main discipline, not a side feature?: → Kalender Sync. The only pure sync specialist in this comparison – with hosting in Germany, Free/Busy by default and real live sharing into other people's calendars, which no other tool here can do.
You're in the DACH region or have compliance requirements?: → Also Kalender Sync. The only tool with hosting in Germany (Hetzner) and a DPA offer.
You want a Swiss-army knife with booking links and unified view, and a US vendor is fine?: → OneCal or CalendarBridge. Both offer sync + booking links + unified view from one tool.
You also need contacts and tasks in the sync?: → SyncGene (or CiraHub going forward).
You want AI to plan your whole day?: → Reclaim.ai.

Ready for calendar sync without a privacy compromise?

Connect your calendars in a few clicks – GDPR-compliant and hosted in Germany.

Try free for 30 days

Currently supported providers

Google Microsoft Apple iCloud KSuite iCal-Feeds

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