Elon Musk announces AI updates to X recommendation algorithm

Elon Musk has announced two significant updates to the X timeline recommendation system designed to improve content delivery and user engagement. The updates involve a new AI/SI ranking model and a new retrieval model.

The new ranking model focuses on predicting “dwell time,” or how long a user lingers on a specific piece of content, rather than relying solely on interaction metrics. Complementing this, the retrieval model is being trained to prioritize posts that users are likely to read from beginning to end.

These changes are part of the broader Phoenix ranking framework, which utilizes a transformer architecture adapted from Grok, the AI model developed by Musk’s xAI venture. Musk reported that user engagement is seeing exponential growth, stating that active user seconds on the platform are hitting new daily records.