X Open-Sources Its Ranking Algorithm: Shadowbans in the Open
On 13 August 2026, X open-sourced the code behind its "For You" feed and core ranking engine, publishing it on GitHub under an Apache v2 license [1][2]. The release is roughly 10 to 15 times larger than previous code drops, and it comes with a new "Under the Hood" tool that lets users check whether their posts have been restricted [1]. It is the platform's biggest transparency move since going private — and critics say it is still incomplete.
Story at a glance
What: the code is now public
The release covers the "For You" timeline and the core ranking engine, including the home-mixer feed assembler, the phoenix action-prediction model, and visibility filtering that decides whether a post is shown [1][2]. X says it has removed almost all hand-engineered heuristics, relying on a Grok-based transformer to learn relevance from engagement [1].
Why it matters: the shadowban question
For years, users have accused X of quietly limiting the reach of certain accounts — "shadowbanning." The new "Under the Hood" settings page lets users with 10+ posts in the past month download a JSON file of their account stats to see if any labels or restrictions were applied [1]. X even suggests uploading the file to an LLM to interpret it [1].
Who: X, researchers, and the public
X's VP of Product Keith Coleman says the goal is a "level playing field" and public audit [1]. External researchers verified the ranking "score" independently before launch [1]. Developers can now submit pull requests to improve the algorithm [1].
When: a history of transparency pushes
| Date | Release |
|---|---|
| 2023 | First "recommendation algorithm" code drop |
| 2025 | Expanded open-source release |
| 13 Aug 2026 | For You feed + ranking engine, 10-15x larger |
Where: GitHub and the X app
The code lives in the xai-org/x-algorithm repository on GitHub [2]. The shadowban check lives in the X app's settings [1].
Which: the numbers that matter
What's in the release
| Component | Role |
|---|---|
| home-mixer | Assembles the For You feed |
| phoenix | Predicts engagement (likes, replies, reposts) |
| visibility-filtering | Decides if a post is displayed |
| License | Apache v2 |
What stays closed
X did not open-source the systems that use Grok to predict rule violations, citing the risk of bad actors gaming spam filters [1].
How: a transformer ranks your feed
The ranking system uses a Grok-based transformer model called Phoenix, which predicts the probability of likes, replies, reposts, and clicks, then computes a final relevance score for each post [1][2]. Because the model learns from engagement sequences, X no longer needs most hand-written ranking rules [1].
What next: audit, but with limits
The historical parallel
X first open-sourced its algorithm in 2023 under pressure from regulators and users, then expanded it in 2025 [1]. Each release was bigger, but each also left key systems closed — the pattern continues in 2026 [1].
The future outlook
- Public audits: Researchers and developers can now study and improve the ranking code via pull requests [1][2].
- Shadowban clarity: The JSON tool gives users evidence, but X still controls the interpretation [1].
- Remaining opacity: TechCrunch notes X is more transparent about code but less transparent overall — user metrics, revenue, and government takedown requests stay private [1].
What to watch: whether the open code leads to real changes, and whether regulators push X to open the rule-violation systems too [1].
References
- TechCrunch — X open sources its ranking algorithm, letting users see if they've been 'shadowbanned'
- GitHub — xai-org/x-algorithm
- Tech Weekly — X makes its ranking algorithm open source, allowing users to check for 'shadowbans'
Disclaimer
This content is for educational purposes only. Figures are as of 14 August 2026 and may be revised. Always verify current information before relying on it.