Best SyncThemCalendars Alternatives for Calendar Sync (2026)

The best SyncThemCalendars alternatives for calendar sync in 2026 are SYNCDATE (faster webhook sync, free tier, EU-hosted), CalendarBridge (iCloud and Apple Calendar with native support), and OneCal (scheduling link features alongside sync). SyncThemCalendars works — it syncs Google, Outlook, and Apple Calendar and has a mobile app for management. The reasons people look for alternatives are sync speed (polling vs webhooks), pricing at scale, and platform coverage beyond the core trio.

> Best SyncThemCalendars alternative: SYNCDATE — webhook-driven sync (~4 seconds vs SyncThemCalendars' 5–15 minute polling), free tier for 2 calendars forever (SyncThemCalendars also offers a free tier), €4.69/month for 20 calendars vs ~$4.99/month for fewer, full CalDAV support (iCloud, Fastmail, Nextcloud), privacy-default "Busy" blocking, EU-hosted (Hetzner, Germany), GDPR-compliant. No mobile app — web-only. CalendarBridge is the better choice if you need iCloud + Apple Calendar with native mobile support.

Why People Look for SyncThemCalendars Alternatives

SyncThemCalendars is a legitimate calendar sync tool with a loyal user base. Three issues drive most users to look for alternatives:

1. Sync speed is slow. SyncThemCalendars uses polling — it checks for changes every 5–15 minutes. Add an event to Google Calendar and a colleague might not see it reflected in their calendar for over 10 minutes. For anyone using Calendly, Cal.com, or shared scheduling tools, this delay creates double-booking risk. Harvard Business Review research estimates professionals waste 9% of productive time on cross-app friction — slow sync compounds this.

2. No CalDAV/Fastmail/Nextcloud support. SyncThemCalendars covers Google, Outlook, and Apple Calendar natively. If you use Fastmail, Nextcloud, or another CalDAV-based calendar as your primary, SyncThemCalendars can't connect to it. SYNCDATE supports the full CalDAV protocol.

3. Mobile-first management. This is actually SyncThemCalendars' strength — they have a mobile app. If you need to manage syncs from your phone, SyncThemCalendars is ahead. SYNCDATE is web-only. If mobile management isn't a requirement, the speed and price advantages of SYNCDATE dominate.

The 4 Best SyncThemCalendars Alternatives

1. SYNCDATE — Best Overall SyncThemCalendars Alternative

SYNCDATE is a dedicated calendar sync tool with the same core mission as SyncThemCalendars — keep calendars in sync across providers — but built on a webhook architecture instead of polling.

The defining advantage: SYNCDATE uses Google Calendar push notifications and Microsoft Graph change notifications to detect changes in ~4 seconds. SyncThemCalendars polls on a 5–15 minute interval. For live scheduling workflows, this is the difference between real-time availability and stale data.

Best for: Users on Google + Outlook (or + iCloud) who want the fastest available sync, CalDAV/Fastmail/Nextcloud support, or a lower per-calendar price. Web-only — if you need a mobile app to manage syncs on the go, SyncThemCalendars has the edge there.

2. CalendarBridge — Best for Apple Calendar + iCloud (Multi-Platform)

CalendarBridge specializes in the Google + Outlook + iCloud three-way setup. It's been around longer than most alternatives and has a strong reputation for Apple Calendar reliability.

Best for: Users who need iCloud + Apple Calendar with a proven multi-ecosystem track record. CalendarBridge doesn't have a permanent free tier; 7-day trial only. See CalendarBridge alternative comparison for details.

3. OneCal — If You Need Scheduling Link Features

OneCal adds scheduling link functionality on top of calendar sync — think Calendly-adjacent features for managing availability. If your workflow involves sharing booking links with clients or teams, OneCal packages that with sync.

Best for: Users who want calendar sync AND scheduling link management in one tool. Not recommended if you just need fast sync — you'll pay $5/month for features you won't use, with no free tier to test. See OneCal alternative comparison for a full breakdown.

4. Reclaim.ai — If You Need AI Scheduling Too

Reclaim.ai ($8/user/month) is a full productivity suite — smart scheduling, habit blocks, task integration (Todoist, Asana, Jira), Slack sync, and meeting templates. It's overkill if you just need calendars to stay in sync, but worth knowing about if you want AI-driven scheduling intelligence alongside sync. See our Reclaim.ai alternative analysis.

SYNCDATE vs SyncThemCalendars: Detailed Breakdown

Sync Speed

The architectural difference is the most important one. SYNCDATE uses webhooks: when you add an event to Google Calendar, Google sends a push notification to SYNCDATE in ~4 seconds. SYNCDATE then writes the event to your target calendar. SyncThemCalendars polls on a 5–15 minute interval — it checks for changes on a timer.

This matters for real-world use: if you're scheduling a meeting and your availability needs to be current, 10+ minute delays create double-booking risk. SYNCDATE's 4-second response makes the difference between sync that works in the background invisibly and sync that you have to wait for.

Platform Coverage

SyncThemCalendars covers Google, Outlook, and Apple Calendar (iCloud). SYNCDATE covers Google, Outlook/Office 365, iCloud (via CalDAV), Fastmail, Nextcloud, and read-only iCal feeds. If your workflow involves Fastmail or Nextcloud as a primary calendar, SYNCDATE is the only option in this comparison that supports it.

Price at Scale

Both tools have free tiers for 2 calendars. At the first paid tier:

• SYNCDATE: €4.69/month for 20 calendars
• SyncThemCalendars: ~$4.99/month for fewer

The per-calendar cost advantage of SYNCDATE grows as your calendar count grows. Managing 5+ calendars (multiple work accounts, personal, shared family calendars) makes the difference material.

The Mobile App Gap

SyncThemCalendars has iOS and Android apps for managing your syncs. SYNCDATE is web-only. Once a SYNCDATE sync is configured, it runs in the background without interaction — but if you need to add calendars, check sync status, or troubleshoot from your phone, SyncThemCalendars wins here.

Privacy

SYNCDATE's default is "Busy" — synced events show as time blocked without sharing titles, descriptions, or attendees. SyncThemCalendars has limited privacy controls. For users sharing calendars across work/personal contexts where event details shouldn't cross, SYNCDATE's default is the right behavior.