Blog

A URL shortener service converts a long URL to a much shorter URL. The shortened version is much easier to include in a tweet, comment, or post. For example, http://blog.lauer.bz/2012/03/attack-of-url-shorteners.html would be cumbersome to include in a tweet, but the bit.ly shortened version http://bit.ly/z5DbQX is much more concise. Also, it's easier to track the number of clicks and generate metrics by using a shortened URL.

However, the proliferation of URL shorteners on the net can easily go unnoticed. Users and engineers tend to not think about them. Which ones are good? Which ones are reliable? Which ones have the lowest latency?

There was a recent article in the New York Times about how users tend to get frustrated when a site takes over 400 milliseconds to load (the blink of an eye). If a URL shortener service is unreliable or slow - what kind of impact is that having on your users?

To conduct my unscientific analysis, I took a sample of some popular shortened links (~5000 or so). The following list is ranked in popularity by URL shortening service. The results were surprising. The caveat is that not all of these are publicly available shortener services. For example, youtu.be is Google's shortening service specifically for sharing videos. It's not like you could switch from bit.ly to youtu.be.

Results

I'd say the most surprising result is how slow Facebook's service is compared to Twitter or Google. URL shortening services are obviously useful, but they definitely are not all created equal. Google's service in particular is clearly outstanding in terms of general performance.