# clm_B23CF82119F1

subject: Grok 4 Fast (/record/grok-4-fast.md)  
predicate: context_window  
value: 2M token  
valid_from: 2025-09-19  
valid_to: null  
published: 2025-09-19  
recorded: 2026-11-04  
confidence: 0.95  
status: valid  
assertable: true  
superseded_by: null  
last_updated: 2026-11-04  
checked: 2026-11-04 · its source page states the value and the date  

> We're rolling out Grok 4 Fast as two models: grok-4-fast-reasoning and grok-4-fast-non-reasoning , each with a 2M token context window.

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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