Product Use case Rating
CrashPlan Best Online Backup Service Overall 9
Backblaze Runner-Up 8
IDrive 7
Acronis 6
Carbonite 5

Best Cloud Backup Service

Disasters happen. When your computer is stolen or destroyed in a flood or fire, or your hard drive unexpectedly fails, it's important to have a backup plan that can restore all your important photos and files. Online backup services are an inexpensive way to give you some peace of mind, as they can save the entire contents of your computer to the cloud.

Based on our extensive testing of five services, the best online backup option is CrashPlan, with Backblaze coming in a close second. There's a single feature that puts CrashPlan ahead: unlimited deleted-file protection. This feature, coupled with unlimited cloud storage, provides the most inclusive disaster-protection solution on the market right now.

Online Backup vs. Online Syncing

It's important to remember that online-backup services are different from online-syncing services, such as Dropbox, Google Drive or Box. That's because online backup services have the ability to continually back up every personal file on your computer to a safe offsite data center, while the syncing services handle only items in designated folders.

Additionally, online-syncing services have relatively low upper limits on capacity, unless you pay a lot. Online-backup solutions, in contrast, often offer unlimited storage, allowing you to back up all the personal files on your computer — and sometimes even on external drives — for one flat fee.

The data-traffic flow is different as well, A syncing service will upload file changes from a customer's computer to its servers, then send the file changes to the customer's other machines. With an online-backup service, the data goes from the computer to the server, then stays there. Only when the customer needs to restore a drive or machine does data flow the other way.

In general, however, online backup services handle only user folders and other files designated as personal or "user-generated." They don't  normally back up operating systems or application software.

If you're completely reliant on online-backup services, you'd better have software installation disks and license keys handy if your system gets hopelessly corrupted, or the hard drive dies. Local backup software, which most online-backup services also offer to complement their primary products, can create disk "images" that back up everything on a computer, including application and system software, so that a clone can easily be created on a new disk or a new machine.

How We Tested and Rated

Our testing and analysis focused on three main areas: ease of file restoration, computer-resource usage and the cost-to-storage ratio. These are essential features when looking for an online backup service, since most services will install an application meant to constantly run on your computer.

Other aspects were also taken into consideration, such as data-transfer speeds, user interface, ease of installation and any unique features.

We didn't weigh transfer speeds that heavily, because upload speed is only relevant during your initial upload, which typically takes a couple of days to a week. After the initial upload is complete, only new or revised files are backed up on a continuous or regular basis.

For our testing, we sequentially installed and tested five backup services on a 2011 MacBook Air: CrashPlan, Backblaze, IDrive, Acronis True Image and Carbonite. We used each service to back up a 4.96-GB folder, containing images, video and music, to the cloud — with Acronis being the only exception, since it supported only full-disk backups. After a service's backup was complete, we then restored a large movie file before moving on to testing the next service.

Metrics such as upload and download speed, as well as computer usage, were measured using two OS X applications: Little Snitch 3.5.1 and OS X's Activity Monitor. All tests were run between the hours of 9 am and 8 pm on Optimum's Online Ultra 50 (up to 50 Mbps down and 25 Mbps up) home Internet service in Brooklyn, New York. It should be noted that download and upload speeds rarely come close to those upper limits.

CrashPlan: Best Overall

Ease of file restoration: Fast and easy, from either the CrashPlan application or website
Computer resource usage:
Cost to storage size ratio:
Very good: unlimited storage for $6 per month (or $60 per year)

CrashPlan ( is our Editor's Choice among all online backup services. It provides unlimited online storage (one computer and an unlimited number of external drives) for $6 per month, or $60 per year. There is also a Family Plan, which allows users to back up as many as 10 computers for $14 per month, a little more than double the individual-license price. (The local-drive backup software is free.)

Users can subscribe to CrashPlan on a month-to-month basis, or save money by buying a one-, two- or three-year subscription. Once I purchased a service plan, I was prompted to download and install the CrashPlan application. The application selected my User folder for upload by default, but you can customize these settings to include only desired directories.

Once I designated the files that I wanted to back up, the initial upload began immediately. The upload averaged around 3.5 Mbps, a rapid rate compared to the 2.9-Mbps average backup rate of all the online backup services. To restore a file, I selected the desired file from CrashPlan's application and clicked Restore. The file immediately began downloading to the desktop, clocking a 4.3 Mbps download speed, compared to the 4.2Mbps average.

At rest, the CrashPlan application barely uses any computer resources, but this jumped to about 6 to 7 percent resource allocation during the file-restoration process — fairly high compared to other services, yet still imperceptible to me as I performed other tasks during the download.

You can do a lot of smaller file restorations from the Crashplan website, but for restores larger than 500 GB, Crashplan asks that you use the Crashplan desktop application. (CrashPlan has ended its Restore to Door service, which for $300 would ship an external hard drive with up to 3.5 TB of restoration data to the customer's home.)

CrashPlan offers continuous file backup, in addition to a less-frequent daily or weekly schedule. By default, Crashplan checks for new files every 15 minutes, but this can be adjusted to as frequently as every minute, although that may be fairly excessive for most people. Other services only offer daily or weekly backups, so there's no protection for newly created files. Like many of its competitors, CrashPlan also uses a versioning system that lets you roll back changes to any file to any point within the previous 30 days.

CrashPlan also offers the strongest file encryption of any of the online-backup service we evaluated. By default, your documents are encrypted by a 448-bit Blowfish key, and there are additional options to use your own password or your own 448-bit key. Backblaze, by comparison, offers 128-bit encryption, with the option to also add a password for an added layer of security. Both of these services are extremely secure, but CrashPlan is locked up just a tad tighter.

There's also a mobile application, available for iOS, Android and Windows, which lets you access your backed-up files on the go. The app is pretty straightforward; I was able to navigate through my file directory to my pictures folder and restore an image to my phone. Once that download was complete, I was free to share it via email or Messages, or post it to social media using the iPhone's built-in share features.

CrashPlan offers deleted-file protection, which continues to store a backup copy of files even after they've been deleted from your computer. Services like Backblaze and Carbonite keep deleted files for only 30 days, after which you can no longer retrieve those documents from your cloud backup. CrashPlan's unlimited deleted-file protection is particularly helpful when backing up external drives, since other services would require each drive to be connected at least every 30 days.

CrashPlan lives as both a traditional application and a menu-bar icon. The application allows you to select files, monitor your backup, restore files and adjust settings. Even after you quit the application, CrashPlan continues to run in the background, continuously uploading new content on your computer. The menu-bar icon provides a quick look at your backup status and can easily launch the full application from the menu.

Bottom Line

CrashPlan offers all the features you would want in an online backup service: good value, easy setup and relatively painless file restoration. Your files are continuously backed up, and deleted files are saved indefinitely, so you never need to worry about digital disasters again.

CrashPlan's single-license price is a dollar higher per month than that of Backblaze, our runner-up, but the deleted-file-protection feature is worth the extra money. Plus, CrashPlan's Family Plan, which protects up to 10 computers for a little more than double the single-license price, is hands-down the best value of any backup service currently available.

Backblaze: Runner Up

Ease of file restoration: Fast and easy, can be done only from the Backblaze website
Computer resource usage: Insignificant resource usage
Cost to storage size ratio: Excellent: unlimited storage (including external drives) for $5 per month (or $50 per year)

Backblaze is another strong contender in the online-backup-service space. It's small and sleek, and offers all the features that you'd expect from an online-backup service. It's also the least expensive option available, costing just $5 per month (or $50 per year) for unlimited online storage for one PC or Mac, including backups of external drives.

After registering for an account, I downloaded the Backblaze installer, which set up a System Preference pane rather than a stand-alone application. The Backblaze preference pane offered just the essential information: the ability to back up now, options for restoration and settings.

The entire Macintosh HD was selected for backup by default, although certain folders and file types were automatically excluded — including the Application and System folders, and .DMG (installation) and .SYS (system) files. These omissions make sense for most people, and each can be overridden by adjusting the app's settings.

The initial upload to Backblaze was slower than that of other services we tested, averaging about 0.7 Mbps when measured with Little Snitch. Speeds did sometimes jump to 4.1 Mbps (Backblaze does not display the current transfer rate). These upload speeds were confirmed using Backblaze's own speed-test tool to estimate a user's total upload time, but the speeds fell shy of the 2.9-Mbps uploads-speed average. (Since this review was first published, Backblaze has updated the upload protocol for improved speed.)

Restoring files can be done only through the Backblaze Web interface. Once I selected a movie file to restore, I had to wait approximately one minute for the download to be ready; when it was ready, I was notified by email. Download speeds for that restoration averaged 4 Mbps, which is pretty close to the 4.2-Mbps average for all the services we tested.

For larger restorations, Backblaze offers two different services, depending on the size of the desired restoration. For $99, Backblaze will mail you a USB flash drive that can hold up to 128 GB of files; for $189, you can get an external hard drive that holds up to 4 TB of data. Backblaze gives  users the option of keeping the storage drives after the restoration process is done, or returning them within 30 days for a full refund via the Restore Return Refund program. (Customers pay for the return shipping.)

File encryption in Backblaze starts on your personal computer, with all your documents being locked with a 128-bit AES symmetric key and transferred over a secure SSL connection. Additionally, you can add your own password to protect your data even further, providing an additional level of protection to your files. (There's now also a two-factor verification option for even greater security.)

Like CrashPlan, Blackblaze offers continuous file backup, which means the application will switch between scanning for new files and uploading them. According to Backblaze, for most computers "this results in roughly one backup per hour." Scans use very little in system resources, and the application was rarely distinguishable in my Mac's Activity Monitor.

Unlike CrashPlan, Acronis or Carbonite, Backblaze doesn't make local-backup software. But its website does have a very good, thorough guide to performing all kinds of backups that shows you how to use built-in Windows and Mac software for local backups.

Backblaze has a companion mobile app for iOS and Android, but it leaves a lot to be desired. The biggest frustration for me was that I had to input my email and password every time I launched the application. (However, the mobile app can now sign you in automatically, and has added support for Apple's Touch ID fingerprint reader.) Additionally, the app doesn't allow you to download files greater than 30 megabytes, so you'll need your computer to restore anything bigger than a forgotten document or presentation.

If you've accidentally deleted a file, you have 30 days to restore it from Backblaze before it's permanently deleted from the company's servers. That's usually plenty of time, but is still inferior to Crashplan's unlimited deleted-file protection. (Backblaze's versioning system likewise has a 30-day time limit.)

Bottom Line

Backblaze is a slim and lightweight online backup service that definitely won't break the bank. The dead-simple application means that you'll be starting your initial backup in no time, and file restorations can be done from any computer using the Web interface.

Backblaze is excellent if you're looking for the cheapest online backup option that still offers serious file protection. But if you have multiple computers to back up, or want unlimited retention of deleted files, CrashPlan is the better choice.


Ease of file restoration: Fast and easy, from either the iDrive application or website
Computer resource usage:
Insignificant resource usage
Cost to storage size ratio:
Fairly expensive: $70 per year for 1 TB

Like Acronis, IDrive charges according to the amount of storage used, rather than charging a flat fee for unlimited storage space. Aside from its free 5GB plan — which makes it more like a Dropbox competitor than an online backup solution — the cheapest IDrive option offers 1TB of storage for $70 per year, although you'll get a 25 percent discount for the first year. The next tier up is 10TB for $500 per year.

There's a good chance that 1TB of storage space will be more than enough for all your important files — at least initially. Furthermore, IDrive allows backups of an unlimited number of devices, be they PCs, Macs, external drives or smartphones (see below).

The catch is that IDrive, like CrashPlan, doesn't remove deleted files from storage. This is a bonus when you have unlimited storage space, but otherwise, the deleted files can quickly add up and require maintenance to keep the overall used space below that 1TB limit.

The IDrive application is fairly straightforward, allowing users to select which folders in their Macintosh HD directory they want to back up. I observed transfer rates of around 4 Mbps during the backup, despite the application only displaying a 1.5-Mbps upload rate, which means files were actually transferring more quickly than the application showed. The average speed of all the services we tested was 2.9 Mbps, so IDrive was definitely faster.

Likewise, restoration downloads transferred at around 7 Mbps, while the application showed a download rate of only 4.5 Mbps. Both these rates are faster than the 4.2-Mbps average.

Like Backblaze, IDrive offers a service, in this called called IDrive Express, that ships you a physical hard drive containing up to 3TB for large restorations. If you're a paying subscriber, this can be done for free once per year, and costs $60 each time otherwise. There's also a versioning feature called IDrive Rewind, which dials back any file or batch of files to a previous version.

IDrive certainly doesn't skimp on security, offering 256-bit AES encryption with the option to generate your own private key during signup. This level of protection is just a bit less than CrashPlan's 448-bit Blowfish encryption, meaning your files are very safe and secure.

The IDrive mobile app, available for iOS, Android and Windows Phone, works a little differently than the competitors' apps. In addition to allowing users to restore and share backed-up files, you can choose to back up the contents of your phone to your IDrive account. When this is enabled, the IDrive app will automatically upload new images, photos, calendar events and contacts to your cloud-storage account.

IDrive also offers a wireless networked storage drive called the IDrive One that complements the cloud backup with local backup. (You can also use the IDrive software to make local incremental backups or full-disk images on any external drive.) IDrive One cost $80 for a 1TB drive or 128GB SSD, and $100 for a 2TB drive or 256GB SSD. Users of IDrive's free cloud-backup service who purchase an IDrive One will get 1TB of cloud storage gratis for the first year.

I enabled phone backup by flipping a switch in the app, and my photos and videos immediately began uploading to my IDrive account. These files were immediately available through the IDrive website, and I restored a couple of images to my laptop.

IDrive was easy to use, but the lack of unlimited storage means you'll need to monitor the service from time to time, and possibly remove old files if you ever get close to your storage limit.

Acronis True Image

Ease of file restoration: File restoration easy from website, full-disk restoration requires empty storage drive
Computer resource usage:
Insignificant resource usage
Cost to storage size ratio:
Expensive: plans vary, but it's $80 for a year of 1TB cloud storage for 1 computer ($6.67/month)

Acronis True Image is slightly different from the other online-backup services we tested, offering a full system-image backup rather than a backup of simply user files and folders. Applications, files, user accounts, configurations and even the operating system are stored in one compressed file, both locally and in the cloud, although incremental backups are also offered.

The Acronis software is initially inexpensive, at $50 for a one-time purchase for a single PC or Mac. But the price can ratchet up quickly depending on your needs. To get 50GB of cloud backup storage — not much these days — you'll need a subscription for $40 per year for one machine. For three machines, it's $70 per year, and for five, it's $80. Additional cloud storage costs an extra $10 for 250GB, $20 for 500GB, $40 for 1TB and so on, right on up to 5TB, which costs an extra $200 per year.

Befitting Acronis True Image's origins as a strictly local solution, the software can be used to make a backup file to any location, including your own external hard drive, as well a cloud server. This makes possible the optimal backup situation: simultaneous backups to both local and cloud storage. An unlimited number of mobile devices can be backed up as well, but there's no cloud backup offered for external hard drives that aren't used as backup drives.

For 2017, Acronis has added ransomware protection to True Image, as well as two more esoteric features: Acronis Notary, which verifies the content of a backed-up file against the original version, and Acronis ASign, which lets multiple users certify a file with digital signatures.

We selected Acronis' cloud backup service and downloaded the backup and restoration software. Creating a new backup was extremely simple: We just selected our hard drive as the source and then the Acronis Cloud as the destination. (The application was already linked to our account upon installation.)

Upload speeds were fast, around 5 Mbps compared to the 2.9Mbps average. Acronis has finally moved on from its full-disk-only backups, and now supports backups of only user-designated files and folders. In order to restore a full disk, you need an empty external drive on which to store the bootable restore file.

Individual files can be accessed through the Acronis Web interface, which looks a lot like Dropbox, but can access all your computer's files rather than only documents in your Dropbox folder. Our restoration download speeds averaged around 4.5 Mbps, which is slightly higher than the category average (4.2 Mbps).

Acronis offers unlimited deleted-file protection, although the default setting, which users can change, clears out the file after 30 days.

The Acronis mobile app (iOS and Android) is fairly standard. I used it to restore an image and send it to a friend via email. I browsed through my backup to the desired file directory, clicked on the file to download, and was able to view and share the image as soon as it was downloaded. Unlike the Backblaze mobile app, there is no size restriction on file downloads.

Acronis does not support continuous file backup, and is instead set to a daily backup schedule by default, with the alternate options being weekly or monthly. Additionally, the built-in 256-bit AES encryption is not enabled by default, and must be turned on before the initial backup. We performed our first backup before noticing this setting, and had to perform an entirely new full-disk backup to enable file encryption.


Ease of file restoration: File restoration easy from application or website
Computer resource usage:
Insignificant resource usage
Cost to storage size ratio:
Very good, starting at $60/year for unlimited storage space

Carbonite offers three different personal subscription plans. The cheapest is the Basic plan at $60 per year for one computer, followed by the Plus plan at $100 per year and the Prime plan at $150 per year. We tested the Basic plan, which is the only plan available to Mac users, and does not include backups of external drives, backups to local drives, or (strangely) automatic video backup. (More on that later.)

The Carbonite application is more like an FTP program compared to its competitors, as it allows you to browse every file on your computer, whether it's selected for backup or not. The application displays a little icon next to every file that represents the file's status, such as Backed Up, Recoverable or Not Selected for Backup.

All backup files are protected by a 128-bit encryption key, just like with Backblaze. But unlike that service, Carbonite has no option to add your own personal password. The 128-bit encryption, which uses the Blowfish cipher, is secure, but it would have been nice to add another layer of security.

Despite average initial backup speeds of around 1.5 Mbps, slower than the 2.9-Mbps average, the full backup was significantly faster than those of Carbonite's competitors. The total size of the files uploaded was also significantly lower than with every other service. Digging into these discrepancies, I realized that this was because neither the Basic nor the Plus plan includes automatic video file backup. Only the Prime plan offers this feature.

In order to select video files for backup, I needed to navigate to each file's respective folder from within the Carbonite application, select the file and click Back This Up. The Basic version of the application does not allow you to select more than one file at a time, so this was a tedious process for the multiple video files I was uploading.

We reached out to Carbonite for comment, since it was the only online backup service we tested that had this limitation.

"We include automatic video backup in our Prime subscription and make it optional (or manual) in our Basic and Plus offerings," a company spokesman told me. "This approach enables us to keep the price of Basic and Plus lower, making reliable data protection accessible to a wider range of people. And, although it is not an automated process, Basic and Plus customers can backup video files using our standard user interface."

Like most cloud-backup services, Carbonite backs up only "user-generated" files such as music, documents, photos or email messages, not a computer's operating system or third-party software. To back up everything, you'll need a Plus or Prime plan, which lets Windows users back up disk images to external local drives.

Carbonite Prime also includes a service that ships an external drive containing all of your files to U.S. residents. You'll pay only for shipping ($10 for standard, $30 for expedited), but you'll be charged an extra $130 if you don't send back the drive within 30 days.

Restorations through the Carbonite application were also fairly slow, averaging a transfer rate of around 1 Mbps, compared to 4.2Mbps for the category average. Neither the backup or restore progress bars accurately displayed either process's progress, either — both stayed completely empty, despite file-download progress observed by the Little Snitch network monitor, before jumping to fully complete when the file transfer was done.

Carbonite says that this is because the progress bars fill by adding only fully completed files, rather than blocks of data, and that the company is currently working on a more detailed transfer status bar. (After this review was originally published in March 2015, the status bar was updated to show incremental progress.)

The Carbonite mobile app, available for iOS and Android, allows users to access their backed-up files on the go. I was able to easily download and email a PDF file that was part of my computer backup, but I was only able to view, not share, a larger video file that I attempted to restore. (In March 2015, Carbonite raised the size limit on downloadable files from 1GB to 10GB.)

Like the other services we tested, Carbonite offers deleted-file protection, but like Backblaze, it deletes the file after 30 days. Windows users can use a version-history feature to roll back files to any point within the past three months.

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