Updated August 2014
Unlimited online backup plans are just that: plans by online backup service providers that offer an unlimited amount of storage space for your data.
Several years of tax returns, some music, and even a video or two might do just fine on a free online backup plan. A bit more data than that might be well suited with a standard plan from any of the popular online backup services out there.
However, if you have 10,000 MP3s, 40 ripped Blu-ray movies, and a few virtual machines that you can't live without, an unlimited online backup plan is probably a better fit for your data.
Below is a list of every unlimited online backup plan that I could find, ranked by my personal preference based on my experiences with each. There are also business-class backup services that offer unlimited online backup plans, but see my Business Online Backup list for those.
If price is the biggest factor for you, you can skip right to my Price Comparison: Unlimited Online Backup Plans. My Online Backup FAQ, Online Backup Q&A, and Online Backup Feature Comparison Chart pieces might also be helpful.
Backblaze is my favorite unlimited plan because it's super-simple. Few if any would have problem figuring out how install their backup software and get everything important backed up to the cloud.
Backblaze costs $5.00 per month for unlimited online backup for one computer. If you're willing to pay up front for 2 years of service, the price comes down to $3.96 per month.
Another big plus in my book is the clarity by which Backblaze explains their unlimited plan: "There are no limits to how much data you can backup with Backblaze so you can be sure you won't go over any backup limit." No strings there!
CrashPlan Unlimited is another unlimited online backup plan I have no trouble recommending.
Their software is fantastic (very easy to use), the encryption level is high (very safe), and the price is low ($5.99 per month or as low as $3.96 per month with a 4 year prepayment).
A second unlimited online backup plan is also available from CrashPlan called CrashPlan Family Unlimited. The Family Unlimited plan is identical to the standard Unlimited plan but allows backup from more than one computer. This plan costs $13.99 per month, or as low as $8.96 per month when you pay for 4 years in advance.
Carbonite has three unlimited online backup plans, all of which have to be paid one year at a time.
Carbonite Basic comes in at $5.00 per month, Carbonite Plus at $8.33 per month, and Carbonite Prime at $12.50 per month. The more expensive the plan, the more features you get. You can read all those details on Carbonite's pricing page.
Carbonite is a very solid company with a long history (Internet-relative, of course) of keeping data securely backed up. If Backblaze or CrashPlan doesn't fit your needs, Carbonite is a fantastic choice!
Note: Carbonite has removed its unpopular throttling practices for new customers but is still rolling out the removal for existing accounts. This should be complete by the summer of 2014.
Tip: Carbonite's least expensive Basic plan seems to not support backup of videos, but it does - it just excludes them by default. You can remove this exclusion in Carbonite's software.
SOS Online Backup offers two absolutely fantastic unlimited online backup plans, packed with features.
The first is Personal Cloud which runs $5.00 per month when you pay by year, or as low as $3.61 per month when you prepay for 3 years. One computer is supported.
The second plan, called Family Cloud, supports up to five computers and costs $20.83 per month with a 1 year prepayment, or $16.11 per month with a three year upfront payment.
Both of SOS's unlimited backup plans support external hard drives, unlimited versioning, and much more.
Zoolz has one unlimited backup plan, called Zoolz Home Unlimited.
Only one payment type is supported, and it's $199.99 /year, which is $16.67 /month.
You can not pay for Zoolz by month but instead must purchase the plan by year.
The Livedrive Backup plan is Livedrive's only truly unlimited online backup plan and costs $8.00 per month.
One year prepayment brings Livedrive down to $7.00 per month while a two year prepayment will save you a little more at $6.00 per month.
One interesting thing about Livedrive Backup: it's relatively inexpensive, at just $1.50 per month, to add a computer to your account. Some services force you to purchase a higher tiered plan, sometimes with more computers than you need, just to get the other one in your house on the account. Most require another full priced account altogether.
Cyphertite is a small company with just one US datacenter location, but I loved how easy the software was to use and the fact that it's open source.
Cyphertite Personal runs $10.00 per month for unlimited online backup. More than one computer is allowed.
Cyphertite's unlimited backup plan pricing might be a bit higher than other plans on this list, but price isn't always the only thing to consider. In this case, security was a big factor in my ranking. Cyphertite requires the use of a passphrase that you create, meaning no one - not the NSA or even Cyphertite - can decrypt your data without that code that only you know.
Some other backup services add this extra layer of security too, but Cyphertite is the only one I know of that requires it.
Nomadesk is another unlimited online backup plan that I found fast and really easy to use.
With a 1 year prepayment, the longest term you can prepay with Nomadesk, this plan costs $9.00 per month. Month-to-month will run you $10.00 per month.
Bitcasa is unique among online backup services because it appears and functions much like another drive on your computer, albeit a bit slower.
Bitcasa Infinite, their one unlimited online backup plan, comes in at a hefty $99.00 per month if you pay monthly, or $83.25 per month if you pay a year upfront.
Aside from Bitcasa's "hard drive in the cloud" description, it functions as a pretty straightforward online backup service via its ability to mirror any folder on your computer, keeping it backed up all the time.
AltDrive is another online backup service with two unlimited plans: AltDrive Gold for just one computer, priced at $4.45 /month. AltDrive Platinum supports three computers and runs $9.95 /month.
You can get a slight discount per month if you pay annually.