Basic Online Backup

For home users, basic services are easiest to use

Mozy and Carbonite are the most well-known online backup providers. Comparison tests show that Mozy outperforms Carbonite, if ever so slightly. Although Mozy also offers backup services for businesses, the reviews we consulted focus on MozyHome, the online backup designed for consumers.

Several reviewers say that MozyHome's edge over Carbonite used to be much greater prior to January 2011, when Mozy updated its MozyHome pricing plans to eliminate unlimited data storage options. In its place, users can opt for a 50 GB, one-computer plan at a cost of $6 per month or a 125 GB, three-computer plan at $10 per month. Critics say the change has made MozyHome one of the more expensive online backup services available -- at least if you have more than 50 GB of data. If you sign up for a year you get a free month, and you get three months free if you sign up for a two-year commitment. Additional storage is available in 20 GB chunks for $2 more per month. If you don't have much to back up, Mozy offers free online storage of up to 2 GB.

Despite the price, Mozy remains well liked because of its security, features and ease of use. Mozy's security is second to none, reviewers say. Files are encrypted locally (and you can use a personal security key that will prevent anyone -- including Mozy -- from peering in) and sent to servers located in both the U.S. and Europe using a secure SSL connection. The latest version of MozyHome provides automatic local backup to an external hard drive in addition to online backup. The interface earns high marks for simplicity and intuitiveness. And aside from the initial upload, backups and downloads are generally quick. MozyHome also offers a free file-synchronization service called Mozy Stash. Files that are added to the Stash folder on your computer automatically and immediately become available on other computers that have Stash installed on them, or you can access them via web browser or on Mozy's iOS and Android apps.

Carbonite offers a simple, unlimited online backup service.

Carbonite (*Est. $60 per year for unlimited storage) offers many of the same features as MozyHome, and it continues to offer unlimited online storage for one computer. Reviews are generally positive, and Carbonite is a little quicker overall, but Mozy earns higher overall ratings. Carbonite online backup doesn't offer a monthly subscription option, but you can save money by opting for two-year (*Est. $100 for unlimited storage) or three-year (*Est. $130 for unlimited storage) subscriptions. A free 15-day trial is also available. It's compatible with both Windows and Mac OS X.

Reviewers say Carbonite is one of the simplest online backup services to use. After a quick installation, you can choose specific files to back up or the Carbonite client will begin the online backup process based on its default settings (Microsoft Office documents, music files, photos and the like). Keep in mind, however, that all files bigger than 4 GB -- and all videos -- must be added manually unless you have a Carbonite HomePremier account (*Est. $150 per year per computer). A number of reviewers say the process of manually adding large files can be time-consuming. System files cannot be backed up online aside from settings files. A local back-up feature is newly available, but requires either a HomePremier account or Carbonite HomePlus (*Est. $100 per year per PC).

CrashPlan+ best for local backup options

CrashPlan is another online backup service that is enjoying very positive reviews. In fact, experts say CrashPlan is the best choice if you want online and local backup from one provider. The basic version of CrashPlan provides free local backup to an external hard drive or another computer, and you can do offsite backups (with permission) to another computer connected to the Internet, but you will need to put up with ads that some find annoying. To get online backup -- and get rid of the ads -- you need to step up to the subscription-based CrashPlan+ (*Est. $50 per year for unlimited storage). Signing up for a two-year (*Est. $80) or three-year (*Est. $120) subscription can save you money, as can signing up for a plan with a storage capacity of 10 GB (*Est. $25 per year). These prices are for one computer; you'll pay a bit more for a family plan that will cover from two to 10 computers (*Est. $120 per year for unlimited storage).

Reviewers say CrashPlan+ is a great value because you get local and online backup. For the same price as other online backup providers, CrashPlan+ allows you to back up your files in three locations -- online, on another computer and on an external hard drive. You can even back up to a friend's computer as long as they have a CrashPlan account. Plus, CrashPlan+ offers unlimited online backup storage (and unlimited file sizes) for a lower price than its competitors. "CrashPlan has the most bang for your buck," Whitson Gordon writes at Lifehacker.com. Despite the myriad of backup options, reviewers say CrashPlan is relatively easy to use and only takes a few minutes to install, but they warn that CrashPlan's interface isn't quite as user-friendly as Mozy's or Carbonite's.