Threads was originally going to live inside the Instagram app

Meta was working on built-in Threads features for Instagram first to compete with Twitter, which pioneered text-first social media apps. But Mosseri says the team made the “very contentious decision internally” to move the features out of Instagram.

Meta’s team, according to Mosseri, found having Instagram host text posts could be confusing to users since the Twitter-like model is entirely different, where replies and original posts can be equally prominent. Comparatively, on Instagram, and other apps like YouTube and TikTok, replies are subordinated to original posts.

Still, Threads is heavily linked to Instagram. You need an Instagram account to use it, and your profile on both platforms link back to each other. Instagram also adds Threads posts inside of Instagram feeds that invite you to go to Threads to read them.