Design can’t solve all of our problems. Users still need to decide to make good use of the tools available to them. But as we spend more time on social media platforms, it’s important to recognize the strengths of their effects on us. Platforms can mimic and codify the limitations of our offline epistemic environments by only connecting us with people we already know (and giving us the option to filter them out when it’s uncomfortable). Or they can encourage productive epistemic friction by pushing us to consider who to engage with, what topics to avoid, and for how long, so that we consciously shape our own epistemic environments.