Best SyncThemCalendars Alternatives for Calendar Sync (2026)

The best SyncThemCalendars alternatives for calendar sync in 2026 are SYNCDATE (published webhook sync speed, permanent free tier, CalDAV), CalendarBridge (Google + Outlook + iCloud in one tool), and OneCal (sync plus a unified calendar view). SyncThemCalendars works — it syncs Google, Outlook and Apple iCloud in any combination, with plans from $3.99/month for 5 syncs. The reasons people look for alternatives come down to a permanent free plan, a published sync speed, and provider coverage beyond those three.

> Best SyncThemCalendars alternative: SYNCDATE — a published ~4-second webhook sync speed (SyncThemCalendars publishes no sync latency), a permanent free plan for 2 calendars and 2 accounts (SyncThemCalendars has no free tier, only a 14-day trial), €8.99/month for 20 calendars, full CalDAV support (iCloud, Fastmail, Nextcloud), privacy-default "Busy" blocking, and EU hosting (Hetzner, Germany). CalendarBridge is worth a look if you want the AI Executive Assistant alongside iCloud support.

Why People Look for SyncThemCalendars Alternatives

SyncThemCalendars is a legitimate calendar sync tool. Three things drive most people to look for alternatives:

1. No permanent free plan. SyncThemCalendars offers a 14-day trial with no credit card, then you pay — their pricing page lists only three paid plans, starting at $3.99/month for 5 syncs. If you want a free plan to run indefinitely on a small setup, SYNCDATE's covers 2 calendars and 2 accounts forever.

2. No published sync speed. Neither the SyncThemCalendars homepage nor their pricing page states a sync interval or latency — the closest wording is that it keeps calendars in sync by "automatically copying events between them". If real-time availability matters to you (for Calendly, Cal.com or shared scheduling), a tool that publishes its speed lets you plan around it. SYNCDATE publishes ~4 seconds via webhooks. Harvard Business Review research estimates professionals waste 9% of productive time on cross-app friction, and stale calendar data feeds double-booking risk.

3. No CalDAV / Fastmail / Nextcloud support. SyncThemCalendars covers Google, Outlook/Office 365 and Apple iCloud. If your primary calendar lives in Fastmail, Nextcloud or another CalDAV service, it's not on their list. SYNCDATE supports the full CalDAV protocol.

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 — built on a webhook architecture.

The defining point: SYNCDATE publishes its sync speed. It uses Google Calendar push notifications and Microsoft Graph change notifications to detect changes in ~4 seconds, with a 15-minute polling fallback. SyncThemCalendars publishes no sync latency, so we can't put a number on theirs.

Best for: People on Google, Outlook or iCloud who want a permanent free plan, a published sync speed, or CalDAV support for Fastmail and Nextcloud.

2. CalendarBridge — Google + Outlook + iCloud in One Tool

CalendarBridge covers Google, Microsoft 365, Microsoft personal accounts and iCloud, plus other providers via an .ics link, and includes an AI Executive Assistant on every tier.

Best for: People who want Google, Microsoft and iCloud in one tool with the AI assistant, and stay under 8 calendars. See CalendarBridge alternative comparison for details.

3. OneCal — Sync Plus a Unified View

OneCal pairs calendar sync with a unified calendar view across Google, Outlook and iCloud. If you want your calendars in one place as well as in sync, that's its pitch.

Best for: People who want a unified calendar view alongside sync. See OneCal alternative comparison for a full breakdown.

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

Reclaim.ai is a full productivity suite — smart scheduling, habit blocks, task integration (Todoist, Asana, Linear) and AI agents — with a free Lite plan that includes one calendar sync and paid seats from $10/month on yearly billing. It's more than you need if you just want calendars in sync, but worth knowing about if you want AI-driven scheduling alongside sync. See our Reclaim.ai alternative analysis.

SYNCDATE vs SyncThemCalendars: Detailed Breakdown

Sync Speed

SYNCDATE uses webhooks: when you add an event to Google Calendar, Google sends a push notification to SYNCDATE in ~4 seconds, and SYNCDATE writes the event to your target calendar, with a 15-minute polling fallback behind that. SyncThemCalendars publishes no sync speed — no interval, no latency figure — so the honest comparison is "a published ~4 seconds" against "not stated". If real-time availability matters, ask them directly.

Platform Coverage

SyncThemCalendars covers Google, Outlook/Office 365 and Apple iCloud, in any combination. 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

SyncThemCalendars has no free plan — a 14-day trial, then $3.99/month for 5 syncs, $7.99 for 16 or $17.99 for 36 (their annual prices are exactly twelve times monthly; they state no discount). SYNCDATE has a permanent free plan for 2 calendars and 2 accounts, and Plus at €8.99/month for 20 calendars. So the free tier is the clearest split: SYNCDATE has one, SyncThemCalendars doesn't.

Privacy

SYNCDATE's default is "Busy" — synced events show as time blocked without sharing titles, descriptions or attendees, and you opt in to detail copying. SyncThemCalendars doesn't publish its default behaviour, so check it before assuming your event details stay private across a shared calendar.