Google Calendar Sync: We Have Choices


A little while ago, Google (s goog) released a free iCal-to-Google Calendar sync tool called Calabaration. I don’t believe that Calabaration works very well, given how it generates a new calendar group within iCal and has limitations on how the Google Calendar can then sync to MobileMe. So I reached out to BusyMac, the makers of BusySync, and Spanning Sync, makers of the Spanning Sync application, to see if they wouldn’t mind me reviewing their products. Both companies happily agreed. Here’s what I learned:


Each one:

  • Installs as a preference pane in the System Preferences.
  • Is very easy to configure.
  • Has fantastic support. Also, hats off to both developers for answering so many of my questions and for helping me to diagnose some key problems with sync services.
  • Doesn’t appear to have any tangible impact on system performance.
  • Works with MobileMe, enabling you to view/edit your Google Calendar within iCal, on the MobileMe web site and via an iPhone (s aapl).
  • Has excellent instructional videos, tutorials and documentation.
  • Let’s you perform a reset of the application so that you can start over with clean settings.
  • Has exceptional logging so that if you do come across a problem, it is easy for the developer to help resolve it.


  • BusySync’s primary function is to enable direct editing of iCal calendars in small business environments. The Google Calendar sync feature is just another bonus to the overall package.
  • SpanningSync not only syncs with Google Calendar, it also Syncs with Gmail Contacts. Granted, if you have an iPhone, Apple’s Address Book also lets you sync your contacts with Gmail. The key difference here is that SpanningSync also syncs the contact photo.
  • Pricing. BusySync has a base price + potential upgrade price model. Spanning Sync has a subscription model or an optional flat-fee price.

BusySync – Details

Once you install BusySync, you can configure it via the preference pane. If you are running BusySync as a single user, the only real benefit is syncing your local iCal calendar with Google Calendar.

However, if you are in a multi-user environment, this is where BusySync really shines. In the Bookspan household, we have two Macs and using BusySync solves a key problem: With the three of us, we have many schedules to maintain. Here’s an example:

Using BusySync enables my wife to directly edit my calendar and vice versa. And we both can sync our updated calendars to MobileMe, enabling us to see the calendar info on our iPhones.

We can also make edits offline and BusySync will automatically update the other user’s calendar once the computer is online again. This is also handy, as my wife doesn’t leave her MacBook running all day.

Lastly, setting up Google Sync is pretty trivial. You just provide your Google credentials, specify which calendars you want to sync and BusySync does the rest. Here is an example:

Of course, no software is perfect. It would be great if BusySync supported the ability to sync iCal ToDos. BusySync also can’t sync meeting attendees from iCal to Google Calendar. However, BusySync will sync alarms and meeting attendees from Google Calendar back to iCal.

Spanning Sync – Details

After you install Spanning Sync, you can also configure it via a preference pane. Like BusySync, setting up Google Calendar Sync is very easy. Once you provide your Google credentials, you then specify which calendars and contacts you want to sync and Spanning Sync does the rest. Here is an example:

If you really care about how your Address Book Contacts sync with Google, then Spanning Sync is the tool to have. Using the product, you can specify which contact groups you want to sync, or all contacts. Further, Spanning Sync is intelligent in the way it handles name formatting between Address Book and Google:

The developers are trying to figure out a way to enable Address Book Group support when syncing. If they can achieve this, it would be a minor miracle, as syncing between any Sync Services enabled application does not support this (for example, Microsoft Entourage and Address Book).

During my testing of Spanning Sync, the developer released a software update that improved memory usage by 4 times! As an added bonus, syncing performance was also significantly improved.

Finally, just like BusySync, the Spanning Sync application cannot sync iCal ToDos. Further, Spanning Sync can’t sync meeting attendees from iCal to Google Calendar. However, also like BusySync, the Spanning Sync application will sync meeting attendees and alarms from Google Calendar back to iCal.

Conclusion and Recommendation

Both of these products are solid applications that can easily meet your needs. If you are looking for more capability than what Google provides with their CalDAV sync tool Calabaration, then you can’t loose with either BusySync or Spanning Sync.

In order to make BusySync most effective, you’ll need at least two licenses which will run you about $50. This is not inexpensive, although when you look at the value, it’s pretty reasonable. Further, the Developer has not charged for an upgrade in the history of the product.

By comparison, Spanning Sync is a $25/year subscription (which includes all upgrades per year) or you can pay for an unlimited license for a total of $65. I personally am not a fan of annuities, so if you plan to buy Spanning Sync, I recommend the unlimited license. Interestingly enough, Spanning Sync recently introduced a new incentive pricing program. They call it Save 5 + Make 5 — essentially each referral you make saves your friend $5 and you receive a $5 bonus. Not bad.

In the Bookspan household, we have chosen BusySync because of the additional iCal functionality. However, that is not a negative toward Spanning Sync. In fact, if my wife and I didn’t need to edit each other’s calendars, then Spanning Sync would be preferred due to its ability to sync Address Book contacts with GMail Contacts (with the added bonus of syncing photos, too).



Good review. I’m testing Calibration now to sync my work Mac to my Mac at home.

(Quick FYI:

In the Conclusion section, “then you can’t loose with either” should read “then you can’t _lose_”)



Anyone can pointing me at a good program to sync also groups contacts between gmail and apple address applications ?
Spanning Sync does not syncronize groups.
BusyMac is not yet ready for this feature.
The apple itunes (for the iPhone owner) allows only to sync the whole address book and not has groups syncing capabilities …


I use Calgoo for two-way syncing between iCal and gCal. Free to sign-up and the client is free as well. I can sync, Google Calendar, iCal, Entourage and this all syncs with the iPhone. Calgoo can sync on a schedule. What I don’t like is that is throws up an icon in the dock while it is running while it also sits in the menubar, why not just have a menu icon.

You can also run this with Outlook as there is a Calgoo Windows client as well. Calendar syncing only but hey, none if these other apps can sync a to-do list.

Direct download link

Suresh Kumar

i originally used Spanning Sync but found it was buggy and created duplicate calendars admittedly this was when the product was first released, i have no idea what the product is like today..

When i installed BusySync it worked first time without a glitch… however i think its a little expensive when in reality calendar synch is the kind of functionality that i expect to be provided by Google at some point.

So in summary. BusySync is the way forward.. (for the time being)

D Creemer

I completely agree with #6 (James) — I installed BusySync months ago, and other than the occasional (automatic) software update, it just quietly, perfectly does its thing. Highly recommended.

Matthew Bookspan

@everyone – I also looked at Plaxo and Soocial for syncing Google Calendars. I found that these two apps (BusySync & Spanning Sync) were more stable, provided bi-directional sync and had a good user experience to boot.

James Hull

I’ve been using BusySync for months now to sync my GCal with my iPhone. No problems whatsoever. Basically, I installed it and completely forgot about it – until now! Don’t know anything about the others.


I’m using BusySync on 2 of my computers to sync google calendar and it works great.


Have you tried Sync’Em from yet? They have just released a 1.18 update that they claim brings it to a stable state (the app is quite new).

Matthew Bookspan

@Jason – valid point. The Spanning Sync folks use their own servers update their bits on the back-end without forcing you to upgrade the client. You can view this as a negative or a positive.


Another point of differentiation between the two is with BusySync communicating directly with Google while Spanning Sync communicates with the company’s servers which then works with Google. With your tinfoil hat squarely fitted this may introduces issues of security, privacy, and reliability.


I’ve been using the google calender and iCal sync. I find that it’s okay for what it is, but yes, there is alot of room for improvement.

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