The 140-character spike

I don’t intentionally set out to do so, but I’ve noticed my tweets gravitating towards Twitter’s character limit. Sometimes it’s the result of a too-long idea being meticulously edited down to size; sometimes it’s purely chance. Either way, it’s oddly satisfying to post a tweet with exactly 140 characters.

How often do tweets max out their character limits? What’s the average length of a tweet? To answer these questions, I turned to a set of tweets collected by Chang, Caverlee, and Lee in the fall of 2009. Filtering out retweets, I was left with over four million of them, of which over 2% used their entire 140 characters.

The shape of the character distribution is fascinating. One-word tweets are understandably very rare, but it doesn’t take long for the distribution to reach its first mode at 35 characters. The curve gradually and smoothly trails off to a local minimum around 116 characters, before positively spiking after 135. The average length is a bit more than 68 characters and the median a bit lower at 62. It looks like a lot of tweetable ideas can be expressed in five or ten words, and there’s a lot of people valiently trying to squeeze in something that’s slightly too big for the text box.

I’m curious whether the spike at 140 characters has more to do with where the character limit is set or the very fact that there is one at all. Since the initial publication of this post, Twitter has doubled the number of characters it allows in a tweet. How has this affected the distribution of tweet lengths?