If you’re out there looking for a Ruby on Rails version of free PHP hosting, there are a few options to choose from.Your first choice is going to be Heroku. They are the absolute leader in free Rails hosting. Their free plan offers a single dino and shared server space to get you up and running for free. The free tier works well for staging, testing, and running small apps. If your app grows and you get a ton of traffic the option to upgrade to a paid plan is simple and hassle free. Your second choice is HelioHost. The free plan from HelioHost includes "unlimited" bandwidth and .25GB of disk space, as well they offer Mongrel, Passenger, and Rails 3.0.3. HelioHost does not however offer SSH or the ability to run more than four applications on one plan. Third, check out AlwaysData. The free plan from AlwaysData offers .1GB of disk space, and 1GB bandwidth. AlwaysData's free plan also comes with restrictions such as forbidding the use of your account for profit and using your account for hosting proxies. Some companies will also occasionally offer one year of free Rails hosting in lieu of another year (or so) of paid hosting service on contract. HostingRails is one such company. They are currently offering one free year when you sign up for a "stacked", shared hosting plan. The price moves up to $7.95 a month after the first year of service and the starter plan offers the use of Mongrel, Passenger, 10GB of disk space and 100GB of bandwidth.
With that being said, and the free options laid in front of you, your best bet is actually not to go with free hosting. Rather, your best option is to start with a cheap shared plan and move up from there when the need arises. I say this because with free hosting you won’t be getting the same service level as a paid customer, and service is important. Paying for your hosting more or less gives you the right to complain and have your provider be obligated to do something about it. Also by going with a cheap shared hosting plan instead of free hosting you gain much, much more control over your server space. Paying 5-10 dollars a month often (not always) gives you the ability to install any gems you want, get data in and out without special tools, among many other benefits. As such it is my personal opinion that you are better off paying for a cheap hosting account rather than paying in frustration for free hosting.
There are quite a few hosts with cheap starter options, let me list a few:
There are many more options, if you aren’t interested in any of these, check out our list of hosts and their available plans to find something you like.