Recommendation SystemVerified
Reviewed and published by trentmaziarz, April 22, 2026. Discovered and drafted by our automated research pipeline.
X deployed a Grok-powered AI ranking system to determine which posts appear in users' feeds, replacing the platform's prior rule-based recommendation algorithm. The system reads every post and video to predict which content each user is most likely to find interesting.
Details
In October 2025, Elon Musk announced that X's recommendation system would be fully powered by Grok, replacing legacy heuristics entirely. By November 2025, the Following feed began being sorted by Grok rather than chronologically. A Rust-based open-source version of the algorithm was released in January 2026, with a component called Phoenix handling Grok-based ranking. The system also incorporates sentiment analysis, reportedly rewarding posts with a constructive tone.
Products affected
X (platform)For You feedFollowing feed
Sources & Evidence
News Article
Cite this record
Trace Foundation. (2026). X: X deployed a Grok-powered AI ranking system to determine which posts appear in users' feeds, replacing the platform's prior rule-based recommendation algorithm. The system reads every post and video to predict which content each user is most likely to find interesting (data as of 2026-04-22) [Data set record]. AI Trace. https://www.aitrace.org/r/practice/6ed1166c-bf49-4c07-93cc-fe35d3887b5d. Accessed September 7, 2026.
- Stable link
- https://www.aitrace.org/r/practice/6ed1166c-bf49-4c07-93cc-fe35d3887b5d
- Data as of
- April 22, 2026
- Last verified
- April 22, 2026
Other practices by X
ModerationX uses a combination of machine learning models and human review to automatically detect posts that violate its rules, including spam, hateful content, and manipulation campaigns. The system can take action automatically or surface content to human moderators.Creative GenX offers Grok Voice Mode, allowing users to speak questions aloud and receive spoken AI-generated responses, available within the X app and the standalone Grok app. Voice Mode launched in February 2025 for top-tier subscribers and later expanded to all users.ProductivityX offers Grok as an AI writing assistant within the post composer, allowing users to draft, refine, shorten, or rephrase posts before publishing. Users tap a Grok icon within the post composer to access writing suggestions.
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