I’ve noticed an interesting trend among social media marketers lately: they are trying to cram more and more content into each social post. I thought it was common knowledge (not to mention commons sense) that shorter captions tend to perform better on platforms like Facebook and Instagram. I’ve always tried to hold myself to conveying one idea and one idea only in each post. This trend came into focus for me last week in a meeting where the client was actually advocating for paragraph-long captions on their Instagram posts in order to “convey the full story.” I was dumbstruck. But I’m always willing to challenge my own assumptions so we dug into our initial research on optimal post length to make sure we hadn’t missed anything.

Between 5 and 20 words in length perform the best in terms of engagement Click to Tweet
The results are pretty clear. Our research shows that posts between 5 and 20 words in length perform the best in terms of engagement across both Facebook and Instagram. Every 5 additional words in length results in a significant drop in average engagement rate. At about the 70-word mark, high engagement is about as likely as hitting a unicorn with your car.

Screen Shot 2015-08-13 at 3.28.22 PMWhat particularly interests me about these findings is not that people don’t know (at least in a general sense) that shorter posts tend to do better, it’s that many marketers seem to so desperately not want it to be true. I probed a couple colleagues and found a belief that if their content was good enough, it wouldn’t matter if it was too long. Among my small sample set there is a palpable sense that their brand is different.

There are certainly a number of places for medium- and long-form content, but Instagram is not one of them, no matter how much you want it to be. I’m not saying you should treat your social posts as banner ads, but they cannot carry the weight of a complex brand story or narrative. Even lengthy product descriptions get unwieldy and uninteresting on social.

So do yourself a favor. Give yourself a word limit when you are crafting your social posts. Imagine that for every word above 20 you are losing money. Seriously…try it. You’ll be surprised how easy it is to trim that 27-word Facebook post down to 18 words and you’ll be even more surprised by the increases in you core social metrics.

Written by Matt Peters
Matt is the Co-Founder and CEO of Pandemic Labs, and enjoys thinking about, writing about, and talking about social media marketing whenever someone will let him.