You know how easy it is to lose vital files. And so now you regularly back up your system to an external hard drive.

That's a good move, and will protect you in many situations. But what if there's a fire? A flood? A burglary? Any major catastrophe could mean you lose your backup media, as well as your PC, and so for real security you'll need to turn to an online backup service.

It's easy to assume this will be too slow, and certainly your first online backup can take a very, very long time. But after that, the program should only need to upload new and changed files in the folders you've specified, which means performance could be much better than you expect.

A good online backup service may provide other benefits, too, such as synchronising folders with your other computers and generating links for files so you can share them with friends. A web view on your files will make them easily accessible from any device. And sometimes these services even include streaming, so if you back up your music collection then you'll be able to play it from any browser, anywhere.

Which is the best service for you, then? We've put 10 big-name online backup services through their paces to help you decide. Read on to see how they fared and how much they'll cost you. Bear in mind that most providers have more than one plan available, and many offer discounts if you sign up for two or three years rather than one, so it's worth looking around and thinking about the capacity you'll need.

Backblaze

Unlimited for $50 (around £32/AU$56) per year
3/5

Best online backup: 10 services tested

Perhaps the ultimate in hassle-free online backup services, the Backblaze PC or Mac client can be downloaded, installed and running within a couple of minutes. There's nothing to set up, the program just automatically searches for and saves all of your personal files, on your system and even external drives.

This simplicity does come with a distinct loss of control, though. In particular, you can't tell Backblaze to back up a specific set of files or folders. The program will always aim to back up your entire hard drive (with the exception of system and application files), and any external drives you might have connected, and the most you can do is tell it to ignore certain folders.

The configuration options you do get are also relatively limited. There is a scheduler, for instance, but it can't do more than run your backup once a day. You don't even get to choose the precise starting time (it has to be at the start of an hour).

And there's also a distinct lack of features, with no sync and no file sharing. And deleted files, along with old file versions, are deleted after 30 days. Restoration is at least easy via the web interface, though, or mobile app (iPhone only), and you can optionally have files sent to you on a flash or USB hard drive.

If you're looking to back up all your data, and don't need any other extras, Backblaze may appeal: it's fast, reasonably priced and easy to use. But if you're ever likely to require more control over your backups, we would look elsewhere.

Find out more about Backblaze

Carbonite Home

Unlimited for $59.99 (around £39/AU$67) per year
3.5/5

Best online backup: 10 services tested

If you prefer a backup service that you can install and forget about, then Carbonite might appeal. You don't have to tell it what to back up, since by default the Windows and Mac clients will protect most of your user files (desktop, music, pictures, the Documents folder). Unlimited storage space means you'll have no worries over file management. And there are very few configuration options to worry about, so anyone should be able to use the program right away.