Let’s suppose for whatever reason I wanted to list my favorite TV stations, and I came up with this list:

cnn.com abc.com cbs.com nbc.com amc.com hbo.com fox.com

It’s not a long list — in fact, including spaces, it’s only 55 characters. Twitter’s character limit is 140 characters, so I should easily be able to tweet this, right? Wrong.

Wait, what? I’m not just over the character limit, I’m WAY over it. How is that possible?

Well, it turns out this is a quirk of Twitter’s URL shortening code. Yes, if you have a long link like http://crosswordnexus.com/wiki/index.php?regex=*twit*&searchtype=simple&xmode=on&source=Wiki+%2B+Wiktionary&first=1 it will shorten it. But if you have a very short URL, it will actually lengthen it, sometimes by quite a bit. For instance, if I type “xkcd.com” into Twitter, it gets automatically changed to http://t.co/W1tPuAhAak, which is 22 characters long. In other words, an eight-character string almost triples in length when you type it in. Crazy, huh?