Syncing Apps With Dropbox

Many Mac users are fortunate enough to have more than one machine. Whether it’s a home desktop and laptop, or a home and office machine, it can be very useful to keep some form of continuity between the two systems. This is easy enough to do with individual files — simply using an online service such as Dropbox or Syncplicity to keep everything synchronized between two machines. But what about applications?
This article will explain how easy it is to keep many popular applications in sync between more than one computer. It doesn’t involve putting all your data on ‘the cloud’ — you still have a local copy if a service closes down for any reason. The steps outlined work for the applications noted here, and may well be applicable to a different piece of software you’d like to keep synchronized. We’ve previously written how to achieve something similar for your iTunes library, but will now take the idea a little further, extending it to other apps.
How Does It Work?
Every application on your Mac has some form of preference or library file — this is where all your application data is stored. What this solution proposes is to store this file on the Dropbox server, rather than simply as a local file. It means that whenever the file changes on one computer, the change is automatically copied across to another machine. When you open the app on another Mac, everything should look the same as you left it previously on the other computer.
Is It Secure?
Dropbox is an extremely secure service, encrypting your information before transmitting it across the Internet. In addition, it supports file ‘versioning’ — this means that if you find that your application preferences are accidentally corrupted or overwritten, it’s simple to revert to an older version through Dropbox. If anything, placing your application library or preferences in more than one location is safer that relying on one sole computer.

Existing Solutions
Many of the applications which are bundled with your Mac are able to sync through Apple’s MobileMe service — iCal, Address Book, Mail, Dashboard and Safari Bookmarks for instance. This works great, and you might not need to use the Dropbox strategy for those applications. I’d recommend sticking to MobileMe for these, as it ensures syncing works well with your iPhone or iPod as well as between Macs.
Getting Started
The first step is to create a Dropbox account if you haven’t already. You receive 2GB of storage for free — probably enough for most simple applications — but you can upgrade to more if you’d like to keep a more data-heavy app in sync. The next step is to locate the library file for that application. For the purposes of this walkthrough, I’ll be using Things, a popular task manager.
The location of the library for Things is at:
User > Library > Preferences > Application Support > Cultured Code > Things
The path is likely to be similar for other applications, and a few examples are shown later on.
Moving Files and Syncing with Dropbox
The next step is a little more complicated. Essentially we need to do two things:
- Move the library into your Dropbox folder
- Create an ‘alias’ to tell Things where to find the new library location
First, close the application in question — ensure that it is completely shut down. Before you do anything, back up the library or preferences file — I can’t stress enough that you should make a copy of the file(s) you’re planning to move, to ensure that if you make a mistake at any point you’re able to simply put them back as before.
The next step is to move the library to your Dropbox folder, usually User > Dropbox. It should sync as normal.
At the moment, when you open Things it will still look for the library in the original location. This is no good, and we need to create an ‘alias’ in place of the library to point Things to your Dropbox folder. This takes three steps:
- Right click the ‘Things’ folder in your Dropbox area, and click ‘Make Alias’
- Move the alias which is created (represented by a folder with an arrow) to the original location: User > Library > Preferences > Application Support > Cultured Code
- Rename the alias to whatever the original folder or file was called, in this case simply ‘Things’
Here are a couple of screenshots showing a ‘before and after’ view of our library folder:

Showing the original Things folder, before we moved it to Dropbox

After moving the original folder and replacing it with an 'alias', this is what you should see
Opening Things should now work as normal, with the application automatically being redirected to the new location of your library.
Setting Up Your Second Computer
You then need to follow the same process on your other computer. Providing you don’t have any information in the application, delete the library file and create an alias from your Dropbox folder in the exact same way.
I wouldn’t recommend using both computers at the same time as you’re likely to lose data, but moving from one to the other (and closing Things each time) should ensure that your data is kept in sync wonderfully!
Other Applications
Things is simply used as an example here. A few other applications, along with the location of their library/preferences data are:
- Camino: User/Library/Application Support/Camino
- LittleSnapper: Simply alter the library location in the app preferences
- 1Password: Change the library location in the app preferences (more info
- iTunes: See our walkthrough
- Bento: User/Library/Application Support/Bento
Conclusion
I hope you’ve found the walkthrough easy to follow and feel confident to experiment with syncing application preferences and data between your Macs. Providing you always back up your information first, there’s no harm in trying the process out with any of your favorite apps.
I’d be interested to hear how you get on, and do let me know which applications you end up syncing on a regular basis!
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I use Dropbox to sync my 1password keychain between my two Macs. I have set mine up where I do not use any aliases to make it work. I simply point the app pref or data location to the Dropbox file on the machine. That data appears on the second Mac. Also note that if you are a Time Machine user, it will make backups of your entire Dropbox account on all your Macs. If you do not wish to have 4 copies of the same file, simply exclude Dropbox from your backups on your second machine. This is what I do as I have a PowerMac G5 and a MacBook Pro. It’s just something to note.
There a several comments after the iTunes walkthrough that you link to, asking for more info on where Dropbox comes into the equation for that type of setup. Were those questions answered anywhere?
Is it possible to sync Firefox over multiple computers?
@htiawe – yes you can use Foxmarks. It’s an Add-on for firefox and works for Windows and Mac flawlessly!
Give it a try.
Wow, thanks for this. It never dawned on me to use an alias, but now I can see some great potential here. Cheers.
Wow! I definitely have to give this application a try. I like how you can sync pretty much anything!
This procedure for Things did not work for me – Things gave an error if there was an alias to the folder rather than the real folder in ~/Library/Application Support/Cultured Code (which, by the way, is different from the path you list in the article – it is not in ~/Library/Preferences/etc.)
However, that’s ok. You can simply move the folder to your Dropbox, and when you next launch Things, hold down the option key – it will allow you to select an existing library, and you can just navigate to the folder in Dropbox.
How does Dropbox compare with Sugar Sync? i need to sync some files between both Macs and PCs, and I hear that Sugar Sync is good at that though I have no personal experience with it.
Any feedback on SugarSync anyone?
Nick Ingrao: Thanks but im looking to share the other bits of Firefox. Such as saved passwords, 1passwd can export the password library but it cant be shared between two (or more) computers live. A dream would be to run Firefox directly off Dropbox, without needing to install.
Re: Dropbox and SugarSync, I have tried both, and both work well. Of course, Dropbox is free for up to 2 GB, while SugarSync does not have a free plan. But I honestly prefer Dropbox, for the following reasons:
- in the web interface, you can actually open an html file that is in your Dropbox. With SugarSync, you need to download it first. This way, if I am borrowing a PC on the road, I can still access some of my files that I cannot with SS.
- Dropbox can handle Mac package files well, while SugarSync cannot (yet).
That said, SugarSync adds versioning (i.e., I can go back to older versions of my files in the interface), and it certainly has a nice looking web interface. From a resources point of view, Sugarsync seems to use less RAM but more CPU when idle, while DRopbox is the opposite. (I have both running now: Dropbox is averaging about 0.1% CPU, 48 MB Real Memory, 978 MB Virtual memory; Sugarsync is 1.8% CPU, 36 MB Real Memory, 1 GB Virtual Memory.) SugarSync insists on having their icon in the Dock, while Dropbox hides itself far better.
My one year of SugarSync will be up in September and at that point I’ll need to decide which one to keep. For right now, I’m planning on Dropbox, but that, of course, could change.