The 140-character spike

@rchurchley 2013-02-06

A disproportionate number of my tweets are exactly 140 characters. I don’t know whether that means I’m really good at Twitter or really bad.

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 researchers 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 distribution of tweet lengths in a 2009 dataset (Chang, Caverlee, and Lee)

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.

When I first published this post, I was curious whether the spike at 140 characters has more to do with the existence of a character limit, or the value at which is was set. Perhaps Twitter itself had the same question, because in the intervening years, it doubled the character cap to 280! How has the distribution of tweet lengths changed in the last ten years?

The distribution of tweet lengths in a 2019 dataset (Internet Archive Team)

Thanks to a 2016 change that excluded media attachments and certain at-mentions from the character count, the modal tweet is now much shorter at only 15 characters. The smooth distribution curve is now also interrupted by a 105-character spike — an artifact of a spambot network broadcasting identical horoscopes during the timeline in question. Aside from that, however, the overall shape of the curve is similar to the one from before, including the telltale spike approaching the new, larger character limit.