Dropbox isn’t the only cloud storage and syncing service, but it is one of the most popular. The ease with which it shares files across OSes and hardware makes it valuable to businesses with workers spread across a large geographic area – and for individuals who don’t want to be tied to a single device, as Windows PCs, Macs, Android phones, iOS devices and even BlackBerrys are supported.
Its easy-to-use exterior masks a sophisticated back-end that’s capable of some very clever tricks. Not bad for a service that is, in its basic form, completely free.
Haven't used Dropbox? Here are the basics
Use Dropbox via your browser or directly within Windows – or a combination of the two
If you’re not already using Dropbox, it’s simple to get started. Sign up for a free account at the Dropbox website
and you’ll immediately receive a generous 2GB of storage. When you install the software, a folder will be created on your computer will henceforth sync with Dropbox’s servers – and with the Dropbox folders on any other computers on which you install the software.
It’s easy to determine the state of synchronisation. Files and folders that have been successfully synced are marked by a green tick overlaid onto their icon; ones in the process of uploading or downloading have a blue icon; those files that, for some reason, can’t be synced get a red cross. The Dropbox icon in the system tray also shows these overlays as an at-a-glance status indicator. If you’re using a particular computer only temporarily, and don’t wish to install the software, you can also access Dropbox through a web browser, as we’ll demonstrate later.
Dropbox makes it easy to share files as well as sync. To share a folder within your Dropbox with a colleague, simply right-click it and choose “Dropbox | Share this folder…” This will take you to the Dropbox website where you can enter the email address of the person with whom you want to share the folder. Once they accept your invitation, a copy of your folder will appear inside the Dropbox folder on their computer, with a special icon to indicate it’s shared.
How it works
Dropbox’s desktop application allows you to restrict bandwidth usage
Under the bonnet, Dropbox works in a similar way to most other cloud synchronisation services. Every time you put a file into your Dropbox folder, it’s automatically uploaded to Dropbox’s servers – or, to be strictly accurate, to Amazon’s S3 servers, since it’s these that provide Dropbox’s storage. The speed at which files upload and download varies depending on your network speed; if you don’t want Dropbox to monopolise your internet connection, you can set bandwidth restrictions. To do this, right-click on the Dropbox icon in the system tray, select Preferences and click on the Bandwidth tab in the window that opens.
Dropbox runs fully in the background, so when a file in your Dropbox is edited on another machine, the file will be updated in your folder automatically. If you rename, delete or move a file, that too will be synchronised. If you delete a file from your Dropbox folder on one PC, it will vanish from all your other devices – and, if the folder is shared, from everyone else’s device as well. For this reason, you shouldn’t think of Dropbox as a backup service; however, as we’ll see below, it could save the day if you accidentally delete or overwrite an important file.
Deleted files and previous versions
Dropbox records changes to the contents of files – useful on collaborative projects
The most convenient way to use Dropbox is via the synchronised folder on your computer. However, the Dropbox.com website is absolutely stacked with powerful touches, and you’re missing out if you don’t use it. For example, you can upload files to your Dropbox account from an unsynchronised computer by simply dragging them into your browser. Dropbox will even detect which folder you’ve dropped a file into.
Dropbox’s website also acts as a kind of always-on Recycle Bin. Any files you delete will remain accessible here for 30 days after you’ve removed them, giving you ample time to find and recover data. Restoring a deleted file is simple. Just click the Bin icon that sits immediately next to Dropbox’s search box: deleted files appear in grey. A right-click gives you the option to restore the file to both your own and everyone else’s Dropbox.
Just as files get moved around and deleted during a project, they also get changed, especially in shared projects. People dip in and out of Word documents, adding sentences and excising paragraphs – or they attack PowerPoint documents, moving things around and deleting slides. Sooner or later, someone is bound to make a change that takes some time to correct – or might even be impossible to undo.
Enter Dropbox’s life-saving version management powers. Right-click any file in your Dropbox folder and click “Dropbox | View previous versions”: you’ll be taken to a web view showing every different version of your file from the past 30 days. Radio buttons next to each version allow you to restore any one of these revisions with a single click.
If 30 days isn’t long enough, the Pack-Rat add-on saves deleted files and old versions indefinitely. It’s only available to users with a paid-for Dropbox Pro account, however, and it adds another charge to your annual Dropbox Pro bill.
The only limitation to version control arises when multiple people are working on a shared file at the same time. This creates two (or more) conflicting versions of the file. In this case, Dropbox keeps both files, and appends “(Conflicted copy)” to the filename of whichever file finishes uploading second. This ensures that there’s no data loss – although the job of merging the contents of the two files and resolving conflicts is left in your hands.
Sharing files more widely
Dropbox links each device to a single Dropbox account
You can invite as many people as you wish to share a Dropbox folder, and – until you uninvite them – everything within the shared folder will be available to everyone. Making a folder available to selected others is as simple as entering multiple email addresses when prompted. Bear in mind that sharing folders is recursive – once a folder is shared, everything within it is shared too. However, it’s possible to only share selected items within a folder.
One limitation of using Dropbox in this way is that everyone needs to have the service installed. Since Dropbox is so useful, this isn’t much of an imposition. And as a bonus, if someone signs up as a result of your referral, you’ll receive an extra 500MB of storage.
For one-off sharing of large files, however, there’s a simpler approach. Simply right-click on the file you want to share and select “Dropbox | Get link”. A web page will open in your browser showing a link to the file, and you can share the URL with anyone to enable them to download it. If you want to revoke the link so the file is no longer available for download, click on the cogwheel at the top-right of the screen and select “Remove link” from the dropdown menu that appears. It’s worth noting that this behaviour used to work only for files inside the “Public” folder that’s automatically created when you install the software; in the latest version, however, you can use it to share anything, anywhere in your Dropbox folder.
If you need to share a large number of files between a group, another option is to invest in the Dropbox for Teams service. It’s a pricey offering – US$795 per year for five users, with additional users costing $125 each – but it gives you much more space than a regular Dropbox account: storage starts at 1TB, with an extra 200GB for each user you add. You also receive unlimited version history and file undeletion without having to shell out for the Pack-Rat extra, and the package includes phone support – the only service from Dropbox that does.
Accessing multiple accounts
Perhaps Dropbox’s biggest weakness when it comes to shared projects is the way it links each device to a single Dropbox account. If you need to access resources that are shared with two different accounts, you can’t sync both at once – if you try simply unlinking your Dropbox account and relinking to a different one, you’re liable to end up overwriting one Dropbox folder with the contents of another.
Dropbox suggests that one way to work around this is by creating multiple user accounts on your computer, which will allow two installations of Dropbox to run independently of each other. You can then leave one account active but dormant in the background, while its Dropbox continues to sync, or switch back and forth as required. Alternatively, you can create a shortcut using the “RunAs” command line to open an instance of Dropbox from your secondary user account without having to log in to Windows. Click here for a detailed guide to setting up multiple instances of Dropbox in Windows 7
Getting more space
Simply signing up for Dropbox gets you 2GB of storage for free, and for many purposes that’s ample. Referring other users gets you an extra 500MB per person, to a maximum of 16GB. Dropbox also employs a bit of “gamification”, so you can receive small increases in storage for doing certain tasks: run the “Get started with Dropbox” tour, for instance, and you get 250MB; supply feedback to Dropbox and you get 125MB. All told, it’s possible to garner an extra 750MB of space for free in this way.
The developer also runs occasional community-wide challenges, such as May’s Dropquest II event, which set users a series of riddles to solve with a prize of 100GB of storage space.
For those with more important things to do, you can get more space instantly by digging out your credit card – US$99 a year gets you a Dropbox Pro account, which provides 50GB of storage; US$199 gets you the 100GB plan.
Dropbox’s mobile apps add an extra dimension of usefulness to the service. Dropbox’s official apps are free, and enable even so-called “closed” devices such as iPads to easily share files with desktop PCs and other devices, without any complicated copying procedures.
The iOS apps also support previewing a broad range of file types out of the box – Word documents (including DOCX files), PowerPoint and Excel files, and a range of video and audio files, can be opened from within the app, as well as Apple formats such as Keynote presentations and Pages documents.
On other devices the choice is more limited in terms of previewing: on Android, you get native support for only JPEG, TIFF and GIF images, plus HTML web pages and plain TXT files, although Android devices typically include their own support for viewing additional file formats, and all Dropbox mobile apps will hunt through your device for apps that can open the different formats. Usefully, if you mark a file as a Favourite within a Dropbox app, that file will be automatically synced to your device and can then be accessed even when you find yourself offline.
Is Dropbox safe?
Dropbox is terrifically convenient for sharing personal documents and professional projects – but is it safe for sharing sensitive documents?
Embarrassingly, the service doesn’t have a perfect security record: in June 2011, a bug allowed users to access any account by typing anything into the password box. The problem persisted for four hours.
When Dropbox is working normally, however, it uses a heavy-duty combination of SSL (Secure Sockets Layer) technology and 256-bit AES (Advanced Encryption Standard) encryption – ensuring that even a determined hacker is unlikely to be able to break into your account.
If you’re running a Dropbox for a client, you should still tread carefully. By default, Dropbox’s employees can’t access the contents of your files, but they can read file metadata (such as filenames, file sizes and the EXIF data attached to images). What’s more, in the event of a court order being issued that affects your account, your files will be subject to US law. Dropbox states that it will supply files to a law enforcement agency if it has “a good faith belief” that disclosure is needed to comply with laws, protect a person’s safety or prevent fraud - and it will remove all of the Dropbox encryption before supplying them.
This means that those with vulnerable clients – schools, for instance – would do well to double-check before sending private data to Dropbox. A possible precaution might be to apply your own encryption to any sensitive files you wish to commit to the service.
UPDATE: Since this article was written, Dropbox has increased security by making available a feature called two-factor authentication. If you decide to turn this feature on, whenever you log in to your Dropbox account you will also need a separate code - a new code is created for you every time you log in. The idea is that even if someone gets hold of your password, they won't be able to access your Dropbox without the code.
Want to get more technical? Creating apps with the Dropbox API
Dropbox offers an API that makes it easy for developers to build Dropbox access into their apps – you can save documents directly to Dropbox in iOS’s iA Writer, for instance – and even to create full-on replacements for Dropbox’s own apps. For users, this means a single Dropbox account can become more useful as you gather apps that connect to it; for developers it means that if Dropbox doesn’t do exactly what you want it to, it’s possible to write something that does.
System-specific software developer kits are available for iOS, Android and OS X devices, and you can also get generic SDKs for Java, Python and Ruby, allowing you to craft applications for more or less any platform. You can even bring Dropbox features to officially unsupported platforms – an example of this being the BoxFiles app on Windows Phone. The SDKs can be found here
. For those who want to dodge the developer kits, Dropbox’s REST API is the foundation for the SDKs (it stands for “REpresentational State Transfer”). Using the SDKs has its benefits, though, such as a series of tutorials for iOS, Android, Ruby and Python.
The Dropbox API supports two levels of access. The more hassle-free of these allows you to access your app’s own folder within a user’s Dropbox – useful if you want to access data independently of a single PC or mobile device. A good example of this is Check Off, an OS X app that synchronises to-do lists between multiple Macs. Alternatively, you can ask for access to a user’s entire Dropbox folder – but you’ll have to justify why your application needs it. In either case, in the name of user security, there’s an official Dropbox approval process to complete before your application can be used by more than five people.
This isn’t the only measure taken to protect user security. All data access is carried out using SSL, and user authentication is done over OAuth, so application developers never see usernames or passwords. It also means that when a user wants to revoke access, they can do so through Dropbox.com, rather than dealing with individual developers.
In all, it’s a versatile framework and one that’s already been put to some ingenious applications. JotForm is an online service that lets you quickly create web-based forms that can be uploaded to Dropbox – useful if, for example, you’re managing a photography competition on a community website. It’s even possible to host an entire website through Dropbox via sites such as KISSr or foneFrame.