5 Best Calendar Sync Tools and Apps

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Do you have multiple calendars and struggling to reflect your availability across all of them? 

Do you work with different clients and facing double bookings because of it?

Are you facing meeting conflicts in your organization, due to employees' schedules clashing with one another?

In this article, you'll learn about the best calendar sync tools that make it easier to reflect your schedule across multiple calendars.

Let's get into it.

What is a Calendar Sync Tool?

A calendar sync tool is a software program that helps individuals and teams sync their schedules across multiple calendars, reducing the likelihood of meeting conflicts and double bookings.

In simple words, a Calendar Sync Tool clones meetings from one calendar to another, or across multiple calendars, depending on how advanced the tool's calendar sync capabilities are.

Why is a Calendar Sync Tool important?

A Calendar Sync Tool is important because it helps individuals and teams avoid meeting conflicts and double bookings by syncing their schedules across multiple calendars. This can save time and reduce stress related to scheduling. Also, it makes communication simpler across teams, as it gives you the confidence that someone is not gonna book you at a slot that you’re busy with another calendar.

Furthermore, it’s a huge time saver. Imagine having multiple calendars, and as soon as someone schedules a meeting in one of them, you have to manually copy that meeting to all your calendars.

What are the best Calendar Sync Apps?

We’re going to rank the best Calendar Sync Tools and Apps based on their calendar sync flexibility, reliability, ease of use, and general features.

1. OneCal

OneCal Landing Page

OneCal is by far the most configurable, reliable, and easy-to-use Calendar Sync in the market, supporting both Outlook and Google Calendars.

Core Features of OneCal

  • Multi-way calendar sync. OneCal is the only tool in the market that allows you to sync multiple calendars in one go. Using other solutions, if you want to sync 4 calendars, you have to create 12 different synchronizations. With OneCal, you only need 1. This is a huge benefit for power-users, or professionals who manage more than 2 calendars on a daily basis, as it’s a huge time saver, as it takes only 1 minute to sync all your calendars.
    OneCal Multi Way Sync
  • Reliable Calendar Sync. We have dedicated countless hours to developing the most reliable Calendar Sync algorithm, accounting even for the rarest edge cases, and making sure that our customers never face errors while syncing their calendars.
    To add, we’ve set up a monitoring system in place that notifies our team every time a calendar sync fails, handling errors or red flags on the fly. We want to make sure that our users feel confident with our solution, and don’t face scheduling conflicts or confusion.
    OneCal Calendar Sync Sucess
  • Privacy-focused Calendar Sync. We know that privacy is crucial when synchronizing multiple calendars across different Organisations, that’s why we’ve built the most configurable Calendar Sync App in the market, allowing you to choose which meeting properties to sync across calendars. Don’t want to sync the meeting description? Want all the cloned events to have a custom color? You can do that.
    OneCal Calendar Sync Configuration
  • Automatic, Real-time, Fast synchronizations. OneCal is at least 5 times faster compared to the competition. Other calendar sync tools take up to 20 minutes to sync two meeting-heavy calendars, OneCal on the other hand, only takes 3 minutes.
    All syncs are automatic and real-time. This means that as soon as a meeting is created on one of your calendars, it will be synced to all your calendars in real-time.
  • Sync Outlook and Google Calendars. OneCal is one of the few platforms that has support for Outlook and Google Calendars. With OneCal, you can sync multiple Outlook and Google Calendars, in less than one minute.
    Example of two synced calendars
  • Booking Links. OneCal also offers a booking links feature, similar to Calendly. This enables you to share your availability with others, and the ability for them to book meetings with you.
    Illustration of a OneCal Booking Link
  • View all your calendars in one place. With OneCal, you don’t need to juggle between Outlook and Google Calendars to navigate through meetings. We have a Calendar View feature, that allows you to view all your calendars in one place. You can view all your meetings, join conference calls, and much more.
    OneCal Calendar View
  • Excellent Customer Support and Team: What makes OneCal special isn't just its features. It's the way the team values each customer highly.
    OneCal Testimonials Screenshot

OneCal Pricing

Given that OneCal allows you to sync multiple calendars in real-time, automatically, it charges based on the number of calendars you want to sync.

  • Starter ($5/user/month): Connect and sync up to 2 calendars,
  • Essential ($10/user/month): Connect and sync up to 5 Calendars
  • Premium ($30/user/month): Connect and sync Unlimited Calendars
  • Custom/Enterprise Plans

Please refer to the pricing page for more details.

OneCal offers a 14-day free trial, no credit card is required. Sign Up to sync all your calendars, streamline your scheduling, share booking links, and more.

2. SyncGene

SyncGene Landing Page

SyncGene is a tool that lets you sync Contacts, Calendars, and Tasks, it also has support for Outlook and Google Calendar.

Core Features of SyncGene

  • Outlook and Google Calendar Support. SyncGene supports Outlook and Google Calendars, which means you can synchronize Outlook and Google Calendars.
  • Sync Tasks and Contacts. If you also need to sync Contacts and Tasks, along with Calendars, SyncGene is a great option, as you can set up all your syncs in one platform.
  • One-way and two-way syncs. With SyncGene you can sync one calendar to another, or two calendars at the same time.
  • Public sharing links. SyncGene has a booking links feature, that allows you to share a link where others can book meetings with you.

SyncGene Cons

  • Limited calendar sync options. With SyncGene, events are duplicated exactly as they are, leaving no room for choosing what to sync, which can result in undesirable outcomes, such as having private events visible to team members.
  • Only one-way or two-way support. SyncGene offers only one-way or two-way synchronization, which restricts you if you need to sync more than 2 calendars, as you have to create multiple sync configurations to achieve your goal of syncing your calendars.
  • Less intuitive UI. Compared to other calendar sync apps, SyncGene lacks a refined user experience. Furthermore, it might feel a little bit overwhelming, given that they offer sync solutions for Contacts, Calendars, and Tasks.
  • No Calendar view Feature. With SyncGene, you can’t view all your calendars in one place, as it doesn’t offer a Calendar View feature. This means that you have to juggle different calendars or find another app that consolidates all your calendars into one view.

SyncGene Pricing

SyncGene has different prices for Individuals, teams, or enterprises.


Free: Sync 2 sources manually

Premium Yearly: $7.42 per month, up to 5 sources

Premium Monthly: $9.95 per month, up to 5 sources.


Team Premium Monthly: $19 per month, up to 4 members

Team Premium Yearly: $14.92 per month, up to 4 members


Enterprise Monthly: $10 per member

Enterprise Custom: Volume pricing

Want to see how OneCal compares to SyncGene? Read our detailed comparison of OneCal vs. SyncGene.

3. Reclaim.AI

Reclaim AI Landing Page

Reclaim AI is a calendar tool that mostly focuses on smart scheduling, and also has a calendar feature, only supporting Google Calendars.

Core Features of Reclaim AI

  • Google Calendar Sync: With Reclaim, you can sync Google Calendars in real-time.
  • One-way or two-way syncs: Reclaim allows you to sync one calendar to another, or two calendars at the same time.
  • Scheduling Links: Reclaim has a scheduling links feature, that allows you to share a link with others so they can book meetings with you, similar to Calendly.
  • Group scheduling: You can create multi-person booking links, which others can use to book time with a group of people.
  • Smart scheduling features: Reclaim has other Smart Features such as Buffer Break times, Smart 1:1, smart habits, etc. but the focus of this article is calendar sync, so we won’t expand much to them.

Reclaim AI cons

  • Only Google Calendar support: If you’re looking to sync Outlook calendars, or Google Calendars and Outlook Calendars, Reclaim is not the best choice, as it lacks Outlook support. In order to make the sync work, you’ll have to share the Outlook Calendar and import it to Google Calendar. The downside of doing that is that the syncs are not in real-time, and it takes up to 24 hours for new events to sync.
    Furthermore, you’ll have to share each Outlook Calendar and import it to each Google Calendar one by one.
  • One-way or two-way syncs: Reclaim lacks multi-way sync support. If you want to sync more than two Google Calendars, you’ll have to create multiple sync configurations.
  • Basic Sync Options: You can choose to hide every event detail when syncing, but you can’t pick which meeting properties to sync. For example, you can't sync the event titles, but strip the meeting description, location, or other meeting properties.
  • No sync status: With Reclaim, there's no way of knowing if a sync has been completed or is still in progress. This is especially confusing when you want to sync more than 2 calendars together, with multiple syncs.

Reclaim Pricing

Reclaim AI charges based on specific features and limitations that come around them. For detailed pricing, please visit their pricing page.

  • Free: 2 Calendars, 1 sync
  • Starter: $8 per user per month
  • Business: $12 per user per month
  • Enterprise: $18 per user per month

For more details, please visit the Reclaim AI pricing page.

Interested in comparing OneCal with Reclaim AI Calendar Sync? We wrote a detailed comparison of OneCal vs. Reclaim AI calendar Sync.

4. SyncThemCalendars

SyncThemCalendars Landing Page

SyncThemCalendars is a Calendar Sync tool that only supports Google Calendar and offers decent calendar sync configurations.

Core Features Of SyncThemCalendars

  • One-way calendar sync: With SyncThemCalendars you can sync one calendar to another.
  • Choose what to sync: You can choose some properties of the meetings that will be synced over, such as description, title, etc.

SyncThemCalendars cons

  • Only one-way sync support: If you plan to sync more than two calendars, it becomes challenging to sync them, as you’ll have to sync each calendar one by one. For example, if you want to sync 4 calendars, you have to create 12 different syncs.
  • No Outlook Support: If you want to sync Google Calendar and Outlook Calendars, SyncThemCalendars is not the tool for you. The only way to get Outlook sync with Google Calendar is by sharing Outlook with Google Calendar. The downfall is that the calendars won’t stay in sync in real-time, but will have a delay of 24 hours
  • Out-of-date UI and UX: The UI and UX offered by SyncThemCalendars feel dated when compared to OneCal or Reclaim AI.
  • Restricting paid plan: With the paid plan SyncThemCalendars offers, you can create up to 5 syncs, which means that you can sync 2 calendars at most. To sync 3 calendars, it takes 6 syncs, which means it’s not supported. You can sync more than 2 calendars, if you don’t want two-way syncs between them.

SyncThemCalendars pricing

SyncThemCalendars charges based on how many syncs you want to create. As noted, this is quite limiting, as it's not possible to sync 3 or more calendars.

  • $5 monthly or $48 annually, up to 5 syncs.

Interested in comparing OneCal to SyncThemCalendars? Check out our comparison post on OneCal vs. SyncThemCalendars.

5. Zapier

Zapier Landing Page

Zapier is a well-known and used tool in the tech industry (and not only), due to its large number of integrations. Using Zapier, you can configure triggers, which are events that start a workflow. After the workflow has started, you can create multiple actions.

Given this flexibility, Zapier can also be used to sync calendars. You can set the trigger to ‘An event is created in my calendar’ and the action to ‘Copy that event into my other calendar’.

Core Features Of Zapier

  • The trigger - Action workflow is flexible: Given the modular nature of Zapier, it’s obvious that the workflows are very customizable. You can select one trigger, and multiple actions, which can be useful if you want to send events from a calendar to more than one calendar. This can be done by creating multiple actions to a trigger, where each action will send events to a different calendar.
  • Plenty of integrations: Given that workflows are what Zapier does, they have made sure to integrate with pretty much every platform they can. This gives power to the users, as they can automate manual processes into the tools they use the most.

Example of a Zapier flow that clones an event from a Google Calendar to another Google Calendar, triggered by an event creation in a Google Calendar.

Zapier Calendar Sync Example

Zapier cons

  • There is not much room for customizing the privacy of the cloned events. As mentioned, Zaps are workflows; you can choose a trigger and an action. When you set to clone events as an action, you do not have the option to choose whether you want to clone all event properties or not. This is a downfall, as you might want to sync your personal calendar to your work calendar, and you won’t want your co-workers to see your private meeting details.
  • No two-way syncing: Zaps are flexible, but not as much in the context of calendar syncing, as they’re pretty much one-way workflows. For instance, you can’t sync Calendar A to Calendar B, and Calendar B to Calendar A.
  • Depending on the configuration you create, it might lead to tens or hundreds of meeting duplicates across calendars: Being flexible and modular is a good thing, but it comes with the disadvantage that, as a user, you can make mistakes in configuring the the calendar sync automations. For example, if you want to sync two calendars both ways, you’d configure:
    Calendar A → Calendar B
    Calendar B → Calendar A
    Guess what? This is a loop, as Zapier will clone Calendar A events to Calendar B, then the second Zap will clone Calendar B events to Calendar A, and the loop continues.
  • It might get expensive if you sync multiple calendars with many events: Zapier now charges based on the number of tasks you use. If you create Zaps involving calendars with a relatively large number of events (more than 100), you’ll have to pay $29.99 monthly. The number of tasks will increase for each event that gets created in a trigger, as tasks will be executed to clone new events into the target calendars selected in your triggers.

Zapier pricing

Zapier has recently changed its pricing model, as it does not charge per task. Zapier is a free plan, which allows you to consume up to 100 tasks per month. The paid plans are:

  • Starter: $29.99 per month - up to 750 tasks per month
  • Professional: $73.50 per month - up to 2000 tasks per month

Note that you can adjust the number of tasks in each paid plan, which increases the pricing.

Interested in comparing OneCal to Zapier? Check out our comparison post on OneCal vs Zapier Calendar Sync

Which is the best Calendar Sync Tool?

In terms of calendar sync features, OneCal is the top pick due to its multi-way sync function that allows for real-time and automatic syncing of multiple calendars. Its reliable and privacy-focused syncs, support for both Outlook and Google Calendar, and other features also make it the best choice for calendar syncing.

Sign up for a 14-day free trial to sync Outlook Calendars and Google Calendars in real time, avoid meeting conflicts, save time, and keep your personal life private.