# clm_ABC87406F9C4

subject: xAI (/record/xai.md)  
predicate: model_release  
value: Grok 4 Fast  
valid_from: 2025-09-19  
valid_to: null  
published: 2025-09-19  
recorded: 2026-10-29  
confidence: 0.70  
status: valid  
assertable: true  
superseded_by: null  
last_updated: 2026-10-31  
checked: 2026-10-31 · its source page states the value and the date  

> Sep 19, 2025 Grok 4 Fast Pushing the Frontier of Cost-Efficient Intelligence We're thrilled to present Grok 4 Fast, our latest advancement in cost-efficient reasoning models.

What https://x.ai/news/grok-4-fast says, word for word.

## Sources

- https://x.ai/news/grok-4-fast (primary, xAI, published 2025-09-19)

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