Keep your calendars in sync and never get overbooked anymore
Listing updated:June 16, 2026
Works with:
21K+
Overview
reate a synchronization between calendars  with our award winning service :  2 minutes setup, safe and secure, and protects your privacy.

OUR USERS ARE   : 

Freelancers which have multiple calendars and don’t want to be overbooked
Professionals that want to combine their personal and professional availability, without sharing any details of their schedule with co-workers, employees or customers.


FEATURES : 
- Unlimited number of calendars from Google™ (personal Gmail™ accounts or Google Workspace™ accounts), Microsoft™ (Office 365™, Outlook.com), and Apple™ (iCloud™)
- Real time synchronization : Synchronization are immediately reflected in the synced calendar to prevent overbooking
- One way or 2 ways calendar synch : choose 
Control over event details : In the sync settings you can choose if you want to display, hide or even modify the description, summary, visibility, reminders (....) of the event.


FREQUENTLY ASKED QUESTIONS : 

- What does SyncThemCalendars exactly do?

Our service allows you to set up synchronization between calendars. The ability to sync calendars is currently missing in all the leading online calendar services like Google Calendar™. With our tool you can merge calendars and availability


- But why do I need to set up a sync between different calendars?

There may be many use cases for this functionality. Perhaps you're working with multiple clients that require you to use their calendar accounts - this makes it hard to align your availability across all different calendars. You may be an entrepreneur with several businesses and domains and need to convey your free/busy time across. Or maybe you just want to block time on your work calendar based on your private/personal calendar? We support all of these use cases and more.

- Do you work with all the calendar services, such as Google Calendar™, Office 365™, Outlook.com, or Apple Calendar™?

We support Microsoft™, Google™, and Apple™ calendars.

- What do you do with my data?

We won't use your data for other reasons but to copy events across your calendars
Additional information
PricingFree of charge trial
Developer
Privacy policy
Terms of service
SyncThemCalendars will ask for the permissions shown below. Learn more
SyncThemCalendars will need access to your Google account
This will allow SyncThemCalendars to :
Run as a Gmail add-on
Run as a Calendar add-on
View and edit events on all your calendars
See and download any calendar you can access using your Google Calendar
Connect to an external service
View your country, language, and timezone
See your primary Google Account email address
See your personal info, including any personal info you've made publicly available
Reviews
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Dustin McCloud
April 24, 2026
I searched all day for a way to sync a shared webcal and my personal ical but had no luck, until i found this! It works great!
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Kady Chaffin
April 6, 2026
I've only used this minimally so far but from what I can tell, the app appears to be very useful! I do wish there was a bit more editing you could do in the modification of various event texts when not wanting to share all details but other than that, I'm impressed and it's useful!
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Adrian Pryce
December 7, 2025
Seemless process; worked right out of the box with a few clicks and finally got this pesky Outlook - Gmail problem solved.
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Benjamin Møller Jensen
June 3, 2026
Is registered as a free of charge app. It is not. Once setup is done, it suddenly only a trial.
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lexx
May 9, 2026
so far so good. i would like it if you could sync multiple cals like 2 into 1 cal sync. it seems you have to do 2 syncs or multiple caldendars into the one you want
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Bill Gillin
February 16, 2026
Install and setup of sync is very easy. I'm not thrilled with a $3.99 a month. I don't make that many calendar entries to justify. I would use the product if it were free.
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Anton Burnette
July 31, 2025
I recently used this app, and I must say, it delivers on its promises flawlessly. From the moment I started using it, everything worked smoothly, and I couldn’t be happier with the results. It’s user-friendly and incredibly efficient, making tasks so much easier to manage. Overall, I am thoroughly impressed with its functionality and performance. I would definitely give it five stars without hesitation! Highly recommended!
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Tia Joseph
December 18, 2025
A little hiccup while setting it up: when asked to connect second google account, it tried to sign in using another Chrome session, and due to the error, I signed into a new browser session, added the extension to that second account, but now can't link my first calendar to it (says that account already exists using second email and visa versa when I try to add my second calendar to the first account). Hopefully it's smooth sailing from here, so I'm leaving this review to get the extended trial and will update if there are any further issues (just emailed support for help a few mins ago and will wait the 24-48 hrs for their reply).
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Neicee Sweet
May 19, 2025
I absolutely love being able to sink my calendars so that I am not overbooking myself, as a stay at home mom, active member of my church and running two small businesses it sometimes gets very hectic keeping up with my own schedule and switching between calendars can be overwhelming this is a game changer!
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Jamie Daniels
May 19, 2026
Fantastic when juggling multiple calendars for multiple jobs or organizations!
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