PostEaseThe short answer
Instagram has no single algorithm. Each part of the app (Feed, Reels, Explore, Stories, Search) has its own ranking system, and each works the same way: it gathers the posts a person could see, predicts what that person is likely to do with each one, and puts the posts with the best predictions first. Meta publishes what each system predicts in its Transparency Center, and updated the Instagram descriptions in 2025 and 2026.
Across those systems the same few behaviours recur. Will people stop for the post, or skip it in the first seconds? Will they watch it to the end, or swipe through the whole carousel? Will they send it to someone, comment, visit your profile or follow you? A post that earns those reactions travels; a post people scroll past does not.
What each part of Instagram predicts
Meta lists ten or so predictions for each system. These are a selection, in Meta’s own terms, with where each system finds its posts.
| Part of Instagram | Where posts come from | Some of what it predicts |
|---|---|---|
| Feed | Accounts you follow | Swiping through a whole carousel, sharing in a DM, time on the post, visiting the author’s profile, skipping it |
| Reels | Accounts you follow, and reels like ones you engaged with | Watching under 3 seconds, watching more than 95% of viewers of reels the same length, resharing, sharing off Instagram, using its audio, following |
| Explore | Authors you engaged with, and posts like ones you engaged with | Following the author, viewing over 5 seconds, watching over 95%, saving, resharing, “Not interested” |
| Recommendations in Feed | Posts and reels you may be interested in | How informative the post is, visiting the author’s profile, commenting, time spent in Reels afterwards |
What that means for a post
Read the predictions as a checklist of what a post has to earn:
- The first three seconds. Reels predicts whether a viewer watches less than three seconds, and Feed whether they skip the first post. Open with the thing itself, not a slow lead-in.
- A reason to finish. Reels compares how much of a reel a viewer watches with viewers of other reels the same length, so a tight 15 seconds can beat a padded 60.
- Something worth sending. Feed predicts DM shares, and Reels predicts reshares and shares off Instagram. A post a viewer would send to one friend does better than one they would only like.
- A reason to swipe. Feed predicts whether a viewer swipes through the whole carousel, so make each slide earn the next.
- A profile worth visiting. Feed and Explore predict profile visits and follows, so your bio and the top of your grid are part of how a post performs.
- Audio others want to use. Reels predicts whether a viewer will use a reel’s audio in their own.
Followers still decide your Feed reach
Feed starts with the accounts a person follows, so your followers are still your first audience there. Reels and Explore are where non-followers find you: both draw on posts similar to what a viewer has engaged with, from accounts they may not follow. That is the practical difference between formats. A feed post mostly reaches people who already know you; a reel can reach people who do not.
Followers also have controls that skip the ranking. Meta lists “See newest content first”, which shows followed accounts newest first, and Favorites, which moves chosen accounts up in Feed. A follower who puts you in Favorites sees you whatever the predictions say.
A signal for quality
One 2026 detail is worth knowing. Among the signals for posts recommended in Feed, Meta lists one “purely generated by LLM to assess the post’s content quality”, and the system predicts “how informative a post is”. A post recommended to strangers is judged in part on whether it is worth their time, not only on how its followers reacted.
Viewers can see and edit their topics
Instagram announced Your Algorithm on 10 December 2025, starting with Reels in the US. It shows people a summary of the topics Instagram thinks they care about and lets them type topics they want more or less of; it is opened from the icon of two lines with hearts in the top corner of Reels or Explore, or from Content preferences in settings. Instagram has since extended it to Explore and then to Feed, globally in English, as one system: a change in one place applies everywhere.
One detail matters to creators. When a post is recommended because of one of these interests, Instagram labels it, for example “From Running”, and viewers can tap the label for related posts. Instagram has not said how it decides which topic a post belongs to.
What costs a post reach
Most lost reach on Instagram comes from a few avoidable habits. Instagram has said it shows low-resolution and watermarked reels, and reels already posted on Instagram, less, so export clean files at full resolution and make something new rather than reposting. Openings that make people scroll past cost a post in Feed, which predicts skipping. And posts with no reason to share, save or comment give the system little to predict on.
Questions
Does Instagram show my posts to all my followers?
Not all of them, and not in order. Feed ranks posts from the accounts each person follows by its predictions. Followers who choose “See newest content first” or add you to Favorites see you more reliably.
What matters most for Instagram Reels?
Holding viewers past the first three seconds, watching to the end compared with reels of the same length, and being shared, all of which Meta lists among the Reels predictions. Likes and comments count too.
Do shares matter on Instagram?
Yes. Feed predicts whether a viewer will share a post in a direct message, and Reels whether they will reshare it or share it off Instagram. Instagram’s own 2023 explanation also names resharing among the most important Reels predictions.
Does the time I post matter to the algorithm?
For Feed it helps, because Feed starts from recent posts by accounts people follow, so posting when your followers are online gives a post its first reactions. For Reels and Explore the post itself carries more of the weight.
How do I reach people who do not follow me?
Through Reels and Explore, which draw on posts similar to what a viewer has engaged with, from accounts they may not follow. A reel that holds strangers past three seconds and gets shared is the main way in.
Sources
- Instagram, Introducing a new way to see and control your algorithm, December 2025.
- Meta, Instagram Feed AI system, June 2026.
- Meta, Instagram Feed Recommendations AI system, June 2026.
- Meta, Instagram Explore AI system, June 2026.
- Meta, Instagram Reels Chaining AI system, November 2025.
- Instagram, Instagram ranking explained, May 2023.