How Instagram Ranks Reels, in Instagram's Own Words

Most explanations of “the algorithm” are guesses. Instagram’s are not, because the company has written its own down. On May 31, 2023, the head of Instagram, Adam Mosseri, published a post titled “Instagram Ranking Explained” that sets out, surface by surface, what the app looks at when it decides what to show you. The section on Reels is short, specific, and still the clearest public statement of how the format works.

The four signals, in order

For Reels, Mosseri lists the signals “in order of importance”. The first is your activity: “which reels you’ve liked, saved, reshared, commented on, and engaged with recently”. The second is your history of interacting with the person who posted. The post is candid about how thin that history usually is: “it’s likely the video was made by someone you’ve never heard of, but if you have interacted with them” that counts.

The third signal is information about the reel itself, “signals about the content within the video such as the audio track or visuals in the video, as well as popularity”. The fourth is information about the person who posted, “popularity signals such as number of followers or level of engagement to help find compelling content”.

Two things stand out in that list. The viewer’s own recent behaviour comes first, ahead of anything about the creator, which is why the Reels tab can feel personal to people who follow almost nobody. And the creator’s follower count is last, described as one popularity signal among several, not a gate.

What Instagram predicts

Ranking is prediction. The post says the app looks at those signals to guess what you will do next, and names the guesses that matter most: “how likely you are to reshare a reel, watch a reel all the way through, like it, and go to the audio page”.

Reshare comes first in that sentence, and completion second. Both are things a viewer does after the first few seconds, which is the practical meaning of the list: a reel is judged on whether people finish it and whether they hand it to someone else, not on whether they paused on it.

What gets pushed down

The same post lists the kinds of reel Instagram tries to make “less discoverable”: “low-resolution or watermarked reels, reels that are muted or contain borders, reels that are majority text, or reels that have already been posted on Instagram”.

That is the closest thing to a style guide the platform has issued. Native resolution, no other app’s watermark, sound on, no letterboxing, moving images rather than a wall of text, and an original upload rather than a repost.

The 2025 summary

In January 2025, Mosseri returned to the subject in a video on his own account. Hootsuite’s summary of the video reports that he named the three signals that matter most as “watch time, likes, and shares (or sends)”, and that the same three apply whether a reel is reaching people who already follow the account (“connected reach”, in the article’s phrase) or people who do not (“unconnected reach”).

That is a compression of the 2023 post rather than a change to it. Completion became “watch time”. Reshare became “sends”. Likes stayed. The audio page dropped out of the headline list. The order of the underlying logic, however, is the same: the app tries to predict whether a stranger will watch to the end and pass the reel on.

What it means for a creator

Put the two documents together and the instructions are unusually plain.

• The reel is judged by strangers first. Because the viewer’s own activity outranks their relationship with the creator, most of a reel’s audience will be people who have never seen the account. That is where the numbers come from, and it is why a small account can post a reel that is watched more times than it has followers. On the Instagram account of the creator The Platform Post profiled this week, @deni_nzt, a run of reels posted in September 2026 drew ten million views in ten days on an account whose public profile shows a follower count in the low five figures, roughly a thousand views per follower.
• Completion is the test. A reel that people watch to the end is doing the one thing the app says it predicts. The length of a reel is not a ranking signal in either document; finishing it is.
• Sends are the amplifier. Resharing is listed first among the predicted actions in 2023 and named again in 2025. A reel that makes someone want to send it to a friend is the reel that leaves the follower base.
• Reposts, watermarks, mute and borders are penalised on the record, which is a reason to upload native, original video rather than cross-post from another app.

What the documents do not say

Neither post gives weights, thresholds or numbers, and neither promises that the logic is fixed. The 2023 post describes ranking as something the company keeps adjusting. Treat the two documents as a description of intent rather than a formula. It is still more than most platforms have written down, and it is enough to explain the shape of the reels that travel: short enough to finish, native to the app, and worth sending on.