Mouse in the House

URL shorteners. Lots of people use them every day – including the team at WatchMouse. URL shorteners like bit.ly, Google’s goo.gl, Twitter’s t.co, and Facebook’s fb.me are widely used nowadays, but how reliable and how fast are they really?

We took a look at the pros and cons of URL shorteners in March 2010, and thought it only fair to see how URL shorteners are performing one year later.

And, what a difference a year makes! Last year, Facebook’s fb.me was at the bottom of the list in terms of speed, but this year fb.me tops our list joining Google’s goo.gl and BudURL with 100% uptime and a much improved loading speed.

Why (not) using URL Shorteners

There are some obvious pros and cons of URL shorteners.

On the plus side:

• URL shorteners obviously provide useful features like making a long URL shorter (e.g. so it fits easily in a Twitter message)
• They enable you to track and analyze clicks on a specific short URL
• Some URL shorteners like t.co and mcaf.ee also provide some browsing safety by analyzing the target URL for harmful website code or phishing attempts

But on the down side, URL shorteners also introduce:

• An additional single point of failure: when a URL shortener service is down (or corrupt) the link won’t work
• Additional load time for a page to fully load

URL Shorteners Uptime

WatchMouse monitored the most popular URL shorteners from February 24 – March 28, 2011 to find out how they are doing in terms of availability and speed. During that time we monitored 25 URL shorteners and collected the uptime and performance statistics. Uptime is an issue for URL shorteners because it has a direct impact on the uptime availability of the website that the URL shortener actually directs to. The uptime results are shown in the chart below:

Uptime is still clearly an issue for some of the URL shorteners, but what a difference a year makes! Last year Facebook’s fb.me landed at the lower regions of our list. Things have changed dramatically this year and now only fb.me, goo.gl, and BudURL scored a perfect 100%. And to be fair, Twitter’s t.co would also score a perfect 100% if they weren’t blocked from China, which is obviously out of their control.

According to our data, twurl.cc, tr.im and to. appear to be dead in the water and inactive with over 31 days of downtime. Digg.com racked up over 19 days of downtime, while snurl.com had over 14 hours of downtime, making them our worst performers and by far the slowest among the active URL shorteners.

URL Shorteners Speed

The performance results can be seen in the chart below:

Note that we left out the resolve time in this chart, please see the full report for a version with the resolve time included and what it means.

• lnkd.in is the slowest and adds over 700 milliseconds on average to the page load time after the click on a link (excluding the resolve time), which is really way too much for just a URL redirection. This substantially affects the user experience.
• goo.gl is super speedy and does a redirection in just about 100 milliseconds, which is really impressive we think.

Live URL Shortener Status Report

We continuously monitor URL shorteners and share the results publicly through our website portal. The real-time status of each of the sites and a seven-day history can be found at http://url-shorteners.public-website-status.com/. You can also receive Twitter alerts so you know immediately when URL shorteners go down by following http://twitter.com/url_shorteners.

URL Shortener Popularity

It’s not obvious to measure the popularity of URL shorteners, but traffic metric for the domain does give an indication:

This information comes from Alexa and was requested for the five most “famous” URL Shorteners.

Seeing that bit.ly is seeing way more traffic than the others we can conclude they are doing a very good job in terms of availability and speed.

[disclaimer: bit.ly and Twitter are WatchMouse customers]

Methodology and full report

The URL shorteners were checked every five minutes from one of the 58 WatchMouse global website monitoring stations. For each short URL, only the redirection was measured, not the actual loading of the target page. The redirection was expected to complete within four seconds without any errors (like when a server error occurred or if the expected target URL location was not found in the http header). If that time was exceeded, WatchMouse verified the results using another of its monitoring stations and the result was counted as unavailable.

The full report can be found here: Performance and Uptime of URL Shorteners.

What do you think? Have URL shorteners improved dramatically over the past year or is there still room for improvement? We welcome your feedback and comments!