X launches Custom Timelines, a Grok-powered feature letting users pin any of over 75 topics to their home tab, in early access to Premium subscribers on iOS
Ladies and gentlemen, today we're launching one of our biggest changes to π Introducing Custom Timelines This feature allows you to pin a specific topic to your home tab. With support for over 75 topics, you can dive deep into your favorite niche on X. It's powered by Grok's [video]
Context & Ripple Effects
X has been building topic-oriented discovery in stages: developer-built custom timelines were tested in 2022, Communities received improved discovery and search in 2024, and Grok-curated Stories brought AI summaries into Explore for Premium users.
This release moves that direction to the home tab and makes Grok a personalization layer rather than a destination users must explicitly invoke. It also extends an earlier pattern of reserving AI-led product features for paid subscribers.
First-order effects
- Premium subscribers on iOS can make a chosen topic, from a catalog of more than 75, a persistent home-tab destination during early access.
- X gains another native surface for Grok inside its core feed experience, alongside its earlier use in news curation and planned account/text interactions.
Second-order effects
- Topic-based home tabs can concentrate attention around interests that Communities and Explore already target, increasing the importance of how X connects feeds, search, and community discovery rather than treating them as separate products.
- Limiting access to Premium makes personalized navigation part of X's paid-feature bundle, giving the company another in-product reason to test whether AI-enhanced discovery supports subscriptions.
Third-order effects
- If X continues to place Grok inside navigation, curation, and interaction flows, the assistant may become an interface layer across the service rather than a standalone chatbot product.
- The broader product design shifts toward AI-mediated, topic-specific feeds; its durability will depend on whether the experience adds value beyond existing Communities, Stories, and conventional timeline controls.
The trend: Social platforms are embedding AI into everyday discovery and navigation, turning the feed from a single default stream into a set of personalized, topic-led entry points.