Experts agree that all computer owners should use some kind of backup system to protect their important data. If your files are stored only on your computer, you are just a theft, fire or hard-drive failure away from losing everything. Cloud storage services, also called online backup services, are a good alternative to using CDs, DVDs, flash drives or external hard drives, though most experts recommend backing up both locally (to an external hard drive or flash drive) as well as to an online service for absolute peace of mind.
Cloud storage services allow users to store their most important or largest files (such as music and video) on a secure remote server or transfer them to other devices linked in a network. Most services have the same basic features: They allow you to either manually select files to back up or schedule a full system backup. The majority do incremental backups, storing changes to a file that's already backed up on the system within a short time after the change is made (ranging from seconds to hours). Most cloud storage services also offer file versioning, so you can restore older versions of your files, if needed.
More and more cloud storage services now specialize in synchronizing your files across multiple computers and mobile devices, and offering features that let multiple users collaborate and edit files. If you don't have many files, some leading cloud storage providers provide free accounts starting at 2 GB. That's enough to store about 200 MP3s or hundreds of digital pictures. Some of the top file synchronization services up that amount to 7 or even 15 GB, and following a major price cut by Google Drive (15 GB free; $2 per month for 100 GB; $10 per month for 1 TB), storage has become cheaper than ever.
If you need more space, paid monthly or annual subscriptions offer more storage. This is good choice if you want to back up the contents of your entire computer. Many cloud storage services create local backups as well, automatically copying your data to an external hard drive or another computer as well as to the company's servers.
While the cloud storage market used to be dominated by smaller companies like Mozy, Backblaze and SugarSync, bigger players like Google, Apple, Amazon and Microsoft are taking over cloud storage by offering impressive collaborative features (like Google Drive) or easy-to-use cloud services that are built into operating systems (like Microsoft OneDrive). Box, one of the earliest cloud storage companies, is still a major player as is Dropbox, perhaps the best-known online backup provider.
With privacy and security becoming bigger concerns for consumers and businesses, however, cloud storage companies are tightening encryption and other security measures. SpiderOak (Best Cloud Storage for Privacy and Security) bases its entire business model around privacy and security, and doesn't even keep a copy of your password or file names.
We found a number of good reviews for cloud storage services, but details can get outdated quickly. As a result, we focus on the most recent reviews from established tech websites running test reviews or providing details on storage services. User reviews are scarce because most of these services aren't sold by third-party retailers, meaning there are few places to post user reviews, though most cloud storage service reviews have a multitude of comments from users.