How the Threads Algorithm Works: What Meta Has Actually Said

Meta's Transparency Center has a page on the Threads feed's AI system, last updated in March 2025. It describes three steps. The system gathers candidate posts: everything from accounts you follow plus a portion of other public posts that meet Meta's quality and integrity rules. It looks at signals about those posts and about you. Then it ranks them by how much value it predicts each post will have for you. The result is a feed that blends accounts you follow with recommendations.

The page also lists some of the most significant predictions the system makes. None of them come with weights, and Meta says the models change often, but the list is the closest thing to an official description of what matters.

Read the list as a description of a reader, not of a post. The system is guessing how a particular person will react. That is why the same post can do well with one audience and disappear with another, and why there is no universal trick that lifts every post.

Three practical points follow. Replies matter, because a reply is one of the explicit predictions and the signals behind several predictions count replies and replies-to-replies. Time spent matters, so a post that is worth reading slowly is not penalised for being longer. And scrolling past is itself a prediction, which means posts that people habitually skip are a cost, not a neutral miss.

The other half of the system is you. Meta's Help Center says that if you signed up with Instagram, your Instagram information is used to personalise Threads. Profiles created with an email address or phone number do not use it.

The default feed mixes followed and recommended posts. The Following feed shows only accounts you follow, in reverse chronological order, with no recommendations. You can also build custom feeds around topics or people. For a creator this means part of your audience sees your posts in strict time order, while the rest sees them only if the ranking system decides to.

Meta has also adjusted the balance over time. In November 2024 Adam Mosseri, head of Instagram, said Threads was rebalancing ranking to show more posts from accounts people follow and fewer recommendations, and told creators to expect reach from non-followers to fall and reach among followers to rise.

A lot of older advice about Threads is out of date. These are the changes that matter most for reach.

"The first 60 minutes decide everything." Meta's documentation lists engagement signals measured over many windows, from the last 15 minutes to the past month. It does not say a post's fate is sealed in its first hour. Early replies plausibly help, but the hard cut-off is folklore.

"Replies are worth X likes." No weights are published. Replies clearly matter, but any precise multiplier you read online is invented.

"Cross-posted text is penalised." We found no Meta statement that Threads detects or demotes text copied from other platforms. Adapt posts because they read better, not because of a rumoured penalty.