When it comes to shortening links, the brevity of the URL is not the only factor you should consider. Speed and reliability are also important. After all, the main purpose of URL shortening services such as bit.ly and TinyURL are to redirect you back to the original (long) link someone shortened in the first place. You want the redirect to be fast and reliable.
The rise of Twitter and its character constraints has made URL shortening services popular. But which one is the best? Royal Pingdom decided to conduct a test over the past 30 days to put nine of URL shortening services through the paces. Overall, Ow.ly and Bit.ly came out on top, while Tr.im came in dead last (no wonder nobody would buy it).
Pingdom tested two things: the average time it took each service to load a page (overhead) and its uptime. The fastest service was actually Is.gd (with an average load time of 163 milliseconds), followed by bit.ly (261 milliseconds) and ow.ly (289 milliseconds).
Tr.im was the third slowest after Cli.gs and Snip.url. But when it comes to reliability, Tr.im had nearly twice the estimated yearly downtime as the next worse service (Twurl). Even with nearly 80 hours of estimated annual downtime, Tr.im still had 99.10 percent reliability. Ow.ly, however, had 100% uptime, and bit.ly came in second with 99.98 percent. (Is.gd came in fifth).
When both the reliability and speed rankings are combined, ow.ly and bit.ly tie for first place overall, followed by Is.gd and Su.pr. Here is the complete ranking (the scores are the rankings for each test added together):