How Instagram ranks posts: Adam Mosseri breaks down the algorithm

Instagram head Adam Mosseri has shared fresh insights into how the platform ranks and distributes content, offering greater clarity on its recommendation systems. Speaking on a recent episode of the Mixed Signals podcast, Mosseri compared Instagram’s approach with that of rival platform TikTok and addressed common questions from creators.

Mosseri explained that Instagram does not operate on a single, universal algorithm. Instead, it uses multiple ranking systems designed for different areas of the app, such as Feed, Reels, Stories and Explore. When a post is published, it is first shown to a relatively small group of users. Instagram then evaluates early engagement signals—such as watch time, saves and shares—and, if the response is positive, gradually expands the content’s reach. He described this process as similar to an “audition”, noting that the term is a simplified way to explain the concept rather than a technical definition.

He also stressed that reach on Instagram is not determined solely by follower count. Content performance plays a critical role, meaning posts from smaller accounts can still achieve wide visibility if they connect strongly with early viewers. This, Mosseri noted, reflects Instagram’s emphasis on how audiences respond to content rather than the size of a creator’s following.

Another key point was that Instagram’s recommendation systems are context-specific. Each surface within the app evaluates content differently, based on typical user behaviour in that space. As a result, a post that performs well on Reels may not see the same results in Feed or Stories, with ranking models continuously adapting to individual viewing habits.

Mosseri’s comments come amid ongoing calls from creators for more transparency around social media algorithms. While he offered a clearer view of how Instagram approaches distribution, he reiterated that there is no fixed formula for reach. Instead, visibility is shaped by a mix of user behaviour, content performance and context.

Overall, Mosseri’s remarks signal another move towards greater openness about Instagram’s ranking systems, while reinforcing that content distribution is dynamic—driven by how users engage and by growing competition in the short-form video space.