X Launches Grok-Powered Custom Timelines as AI Reshapes Social Media Feeds

X has introduced Grok-powered Custom Timelines, allowing Premium subscribers to pin curated feeds across more than 75 topic categories directly to their home tab. The feature, described by the company as one of the most significant changes to the app to date, uses xAI’s Grok to read and label every post by topic rather than relying on traditional keyword or hashtag signals.

Head of product Nikita Bier noted the feeds perform best for topics users already engage with. Available categories span news, sport, technology, artificial intelligence, finance, and pop culture. The launch coincides with the shutdown of X Communities.

The rollout is currently limited to iOS, with Android support planned. Notably, the second post in each feed is an advertisement, potentially expanding X’s struggling ad inventory.