Saturday, February 28, 2009

Dropbox: A free, low-bandwidth solution for online file sharing, syncronization and backup

One of my projects is the book AIDS Is Real and It's In Our Church, which I co-authored. The English version has been quite a success, Hausa and Amharic editions are in print, and now we're working on the French version. One of the technical problems we've dealt with is simply how to share the files between authors and editors on different continents, while being sure that corrections and updates are made to the right file. Once, in the Hausa version, I spent quite a few hours making corrections and then discovered that the file I'd been given was not the latest.

There are many approaches to this issue, which after all is a common one whenever people are collaborating on documents. One of the particular constraints for some of us though, is that the solution has to be low-bandwidth, simple, and free (or at least very low cost). It simply isn't practical to be uploading and downloading a 20 MB file every time it is changed.

I've looked briefly at Google Docs, which works fine and would be my first choice for documents that don't have a lot of formatting requirements. Collaborators work (even simultaneously) on a document in Google's own format, stored in cyberspace somewhere, and that document can be exported when necessary to another format. Documents can be text (with pictures), spreadsheets, or presentations. Google Docs is free, doesn't require any setup, and lets users work online or offline (that is, you can edit documents even while not connected to the Internet, and they will be saved again when you are online).

Google Docs won't do what I need at the moment, though, which is to allow people to edit Microsoft Word and Publisher documents. That is where Dropbox has been a real help. I use it to
  • Share files with co-workers, automatically keeping everyone's copies synchronized
  • Work on files from different computers without having to do anything manually to keep them synchronized
  • Keep online backups of projects I'm actively working on, so that the backup is always current.
Here's how it works:
  1. Download and install the free software (currently a 14 MB file). It creates a special My Dropbox folder on your computer.
  2. Register as a user with the service. You get a 2 GB online folder free, and can pay for more storage.
  3. "Once installed, any file you drop into your Dropbox folder will synchronize and be available on any other computer you've installed Dropbox on, as well as from the web. Also, any changes you make to files in your Dropbox will sync to your other computers, instantly."
  4. Dropbox does not transfer the entire file each time it is changed, but only sends the changed portions. This means that when I change one word in the 20 MB file, only a small amount of data has to be sent back and forth over the Internet, not 20 MB. That makes it useable over our low-bandwidth connection.
You can use the Dropbox folder like any other folder. Drag files into it, make sub-folders, add and delete files, and so on. All those files and sub-folders will be transparently synchronized with your online folder and with any users sharing those files. That last point is important. People sharing your files do not have to do anything to keep their copies up to date, as Dropbox does that in the background.

  1. I create an "AIDS is Real" folder inside my Dropbox folder and drag my 20 MB aids_is_real.doc file into it.
  2. If my collaborator does not already have Dropbox installed, I send her an invitation to install it.
  3. I mark the AIDS is Real folder as shared with my collaborator, for reading and updating.
  4. The Dropbox software automatically downloads aids_is_real.doc into my collaborator's computer.
  5. I open my copy of the document from my local Dropbox folder, make some changes, then save and close the file (changes are not synchronized until the file is closed).
  6. Dropbox software automatically saves my changes to the online copy and to my collaborator's local copy. When my collaborator opens her copy, it is always up to date (as of the last time she was connected to the Internet).
  7. Likewise, when my co-worker changes the file on her computer, those changes will be reflected in my local copy (almost) immediately.
Give it a try! It's well worth the effort if only for the ability to keep 2 GB worth of your important projects safely backed up online. (Of course, how safely depends on the long-term survival, security, and stability of Dropbox; you shouldn't depend on any one service for the backup of your valuable data).


  1. Well my comment is more like a question, how do you deal with people who do not have access to internet on their laptops and will have to go to cybercafe's and use a memory stick, how do I share information with my collaborator in such circumstances

  2. First, remember that there is no way to have a secure connection using a public computer as in the scenario you describe. Any passwords used and any memory stick should be considered compromised. See the previous posts on that topic, if there is no alternative to using a public computer.

    That said, a person could simply log on to his or her Dropbox account and upload the file from a memory stick. Of course, without real-time synchronization, it's more likely that there will be conflicting changes if more than one person is editing the files. In this case, it's still an easy way to share the data, but you would have to be careful not to edit the files at the same time, or you could use a tool to reconcile conflicting changes.