How reliable is free web hosting you ask? That is a very good question. Free web hosting has the best cost in the business, at least in regards to the upfront costs. Most people are intrigued by anything free, so it is no surprise you would like to know a little bit about it. When it comes to reliability, free web hosting is normally hit and miss. 
With any paid web hosting service, you have a guaranteed uptime, and if you for some reason do experience extended downtime, you will normally be reimbursed with a free month. Free web hosting holds no such guarantee.
It is hard to put a percentage on uptime for free hosts. Some companies randomly cause problems with free hosting in an attempt to subtly encourage the user to purchase the upgraded hosting package. You could go forever without having a problem, or you could get unlucky and have multiple problems a day. It all affects your bottom line. Any time that your web site is down, you are losing possible customers. The lack of a guaranteed uptime is normally a breaking point for anyone considering free hosting.
For sites that lack the constant traffic, the downtime might not affect you much. At the same time, your lack of traffic will in no way guarantee a smooth load for your web page. You are at the mercy of the other users that are on your server. Unlike paid shared hosting, free hosting servers are regularly abused by hackers. The price is good and there are so many to bounce around to. Security is also a risk when using free hosting, due to the shared hosting.
Free web hosting also lacks many of the necessary tools to help your website grow. Most free web host companies put a low cap on the amount of bandwidth, as well as memory you can use. With a lack of bandwidth, your website could be restricted at any time. The worst case scenario is that the web site will go down when you are having an onslaught of traffic. This is a major problem to have when running your business. The free hosting continues to cost you money. It makes you wonder where else free web hosting is lacking.