Source: http://lifehacker.com/5496415/all-url-shorteners-are-not-equal-pick-a-speedy-and-reliable-one
URL shorteners are great for minimizing URLs in a Twitter message or keeping links clean in an email, but as convenient as they are they do introduce an extra point of failure. WatchMouse, a monitoring organization, highlights the best.
A Dutch web-monitoring company, WatchMouse, monitored popular URL shortening services for a period of one month and then analyzed the results. They found a significant amount of variance in the quality of services with 100% uptime and low latency on one end and shaky uptime and long latency on the other.
Shortening service Snurl, for example, had the lowest uptime of any of the services. Only Goo.gl and Twt.tl had 100% uptime. Latency was an issue for many of the shorteners but none quite as bad as Facebook's shortener Fb.me—nearly ten times as slow as the fastest shortener, Goo.gl.
At the moment Google's URL shortener is clearly dominating the market with perfect up time and extreme responsiveness—learn how you can use Goo.gl without a Google account or Google Toolbar here—but since it may not always be so WatchMouse set up a publicly accessible monitoring page to track URL shortening services. You can read the article at the link below or jump to the current monitoring stats here.