X rolls out AI-powered custom timelines for premium users

At a glance:

• X introduces custom timelines that let premium users pin any of 75+ topics to the home tab on iOS
• The feature is powered by Grok AI, which tailors the algorithm to individual interests
• Early access is limited to Premium subscribers on iOS; Android will follow soon

What the feature does

X, formerly known as Twitter, announced on April 21, 2026 that Premium subscribers can now add a new “Add+” button next to the Following tab in the iOS app. Tapping the button opens a catalog of more than 75 topics—ranging from design and robotics to real‑estate—allowing users to pin a chosen subject directly to their home feed. The result is a dedicated timeline that surfaces posts, articles and threads strictly related to the selected niche, while the standard For You and Following streams continue to operate as before.

The rollout is positioned as “one of our biggest changes,” according to a post by X product lead Nikita Bier (@nikitabier) on X. The tweet includes a screenshot of the new UI and reads: “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…”.

How Grok AI powers the timelines

The custom timelines are underpinned by Grok AI, X’s in‑house large‑language model that also powers the platform’s search and summarisation tools. Grok analyses a user’s historical engagement—likes, retweets, dwell time—and then applies a set of filters to surface the most relevant content within the chosen topic. X claims the model “understands the social media platform’s algorithm personalization so that timelines are tuned for individual users,” meaning that even within a broad category like “robotics,” the feed will prioritize the sub‑topics a specific user interacts with most often.

In practice, this means a user who frequently engages with autonomous‑vehicle discussions will see more posts about self‑driving tech and less about hobbyist robotics, even though both fall under the same umbrella topic. X says the filters work “even better for topics a user already engages with,” suggesting a feedback loop that refines relevance over time.

Availability and future rollout

At launch, the custom‑timeline feature is exclusive to Premium subscribers on iOS. Android users will receive the capability “soon,” though no exact date has been disclosed. Existing Premium members will see the Add+ button appear automatically after the app updates; non‑subscribers continue to see the standard tab layout.

X also introduced a complementary tool that lets users snooze topics on the For You tab, effectively muting categories such as politics or sports. This gives users granular control over both the curated For You experience and the newly created topic‑specific timelines.

What this means for the platform

By bundling AI‑driven personalization with a subscription model, X is deepening the value proposition of its Premium tier. The move mirrors trends across social media where paid tiers offer algorithmic advantages—think of Meta’s “Ad‑Free” experiments or TikTok’s upcoming “Pro” features. If the custom timelines drive higher engagement among paying users, X could see a measurable lift in subscription renewals and ARPU (average revenue per user).

Critics may argue that AI‑curated feeds risk creating echo chambers, but X’s snooze tool and the ability to maintain separate For You and Following streams provide a safety valve. The real test will be how the algorithm balances relevance with diversity of viewpoints, especially as the feature expands to Android and potentially to a broader user base.

Looking ahead

X has hinted that future updates could allow multiple pinned topics per user, as well as deeper integration with X Spaces and long‑form notes. For now, the company is gathering feedback from the iOS Premium cohort before scaling the feature. Observers will be watching churn metrics, usage time per timeline, and any shifts in content moderation demands as AI surfaces more niche conversations.