PostInkGuide
The X algorithm, explained: what is known and what is rumour
X has published the code that ranks its For You feed twice, in 2023 and again in 2026. Here’s how it works according to that code, what changed between the two releases, and which popular claims the code doesn’t support.
Two feeds, two rules
Following shows posts from accounts you follow. For You mixes those with posts from accounts you don’t follow, chosen and ordered by the ranking system. Nearly everything people say about “the algorithm” is about For You. In November 2025, Elon Musk said Grok was also ranking posts in Following, with a chronological view still available. X’s help page for the timeline, updated in September 2026, still describes Following simply as posts from accounts you follow.
How For You picks posts, according to the 2026 code
In January 2026, X published a rewritten ranking system, described as using the same transformer architecture as xAI’s Grok. Its documentation sets out the steps:
- Gather candidates. Posts from accounts you follow, plus posts from outside your network. Those are found by a retrieval model, by topic clusters, and from a list of popular posts.
- Filter. Posts older than 48 hours are dropped, among other things.
- Score. A model predicts how likely you are to take each action on each post: like, reply, repost, share, follow the author, or mute, block and report. The score is a weighted sum of those predictions.
- Adjust. Several posts in a row from the same author are scored down. Posts from outside your network are discounted. New authors get a boost.
- Mix and trim. The list is reordered for variety and the top posts are kept. Posts that break the rules are hidden or labelled.
What each action is worth
Here are the weights in the published code as of late October 2026, alongside the ones published in April 2023. Both come with a note from X that they can change at any time.
| Predicted action | 2023 weight | 2026 weight |
|---|---|---|
| Like | 0.5 | 0.66 |
| Repost | 1 | 1 |
| Reply | 13.5 | 5 |
| Reply between people who follow each other | Not separate | +15 on top |
| Reply the author engages with | 75 | Not in the code |
| Quote | Not separate | 5 |
| Share by DM / by copied link | Not separate | 5 / 20 |
| Follow the author | Not separate | 4 |
| Not interested | −74 (negative feedback) | −52 |
| Mute / block the author | In negative feedback | −59 / −31 |
| Report | −369 | −234 |
A common misreading: these weights multiply the model’s predicted probability of each action. They don’t count real actions, so “one report cancels 400 likes” isn’t what the numbers mean. What they do show is the shape. Replies, quotes and shares count for much more than likes, and anything that makes people mute, block or say “not interested” costs a lot.
What changed in 2026
- Conversations between mutuals. In July 2026, X added a boost for replies between people who follow each other. It started at 20 and settled at 15.
- Reading time. In October 2026, the model was updated to better predict how long people spend on a post. Retrieval was also trained to surface posts people read to the end.
- New authors. The code includes a boost for recent posts from smaller accounts with few impressions. It helps new accounts find a first audience.
Popular claims, checked
“Links are punished”
In 2023, Musk said the algorithm optimises for time on X, so posts with links get less attention. In April 2026, X’s head of product, Nikita Bier, said links were never deboosted. The problem, he said, was that opened websites covered the buttons that make a post rank. The published 2026 code has no link penalty. It does have a small weight for opening a link and a large one for people staying to read. So a post that sends readers away still tends to collect fewer of the signals that rank.
“Premium accounts get boosted”
The 2023 code multiplied the score of Premium authors by 4 for people in their network and by 2 outside it. The 2026 code X published has no such multiplier. Still, X’s own Premium page promises subscribers higher placement for their replies, and some parts of the system aren’t published. “Not in the code” doesn’t prove “not in production”.
“Post at exactly the right minute”
Posts stay in the running for For You for up to 48 hours. Timing decides your first audience. What the post says decides whether it travels. There’s more on this in the best time to post on X.
What it means for what you post
- Write things people want to answer, rather than things they can only like. A reply is worth several likes.
- Answer the replies you get. Conversations, especially with people you follow back, are what the current code rewards most.
- Make posts worth reading to the end. Leave out the filler that makes people scroll on.
- Avoid what gets you muted: engagement bait, repetitive posts and replies that read as generated.
That last point is why PostInk exists. Its reply generator drafts in your own voice and discards any draft with the patterns that make readers think “bot”.
Sources
- twitter/the-algorithm on GitHub (2023 release)
- twitter/the-algorithm-ml: heavy ranker weights (5 April 2023)
- xai-org/x-algorithm on GitHub (2026 release, read 28 October 2026)
- Decrypt: X open-sources its Grok-powered algorithm (20 January 2026)
- X Help Center: About your For You timeline
- Nikita Bier, X, on links (8 April 2026)
- Elon Musk, X, on Grok ranking the Following feed (27 November 2025)