# Grok 4 Fast context window

entity: /record/grok-4-fast.md  
predicate: context_window  
page: /record/grok-4-fast/context_window  
as_of: 2026-11-04  

As of November 4, 2026, Grok 4 Fast's context window on the AsOf record is 2 M token, dated September 19, 2025, from a primary source (x.ai). The record holds 1 claim on Grok 4 Fast's context window, 1 still open and 0 superseded, each dated and sourced; a replaced value is closed with an end date, never deleted.

## Current context window

What the record asserts on 2026-11-04.

- [Grok 4 Fast](/record/grok-4-fast.md) | context_window | 2M token | valid 2025-09-19 to present | conf 0.95 | valid | [clm_B23CF82119F1](/claim/clm_B23CF82119F1.md)
  sources: https://x.ai/news/grok-4-fast

## Every dated value

One claim per line, oldest first. Superseded claims stay visible.

- [Grok 4 Fast](/record/grok-4-fast.md) | context_window | 2M token | valid 2025-09-19 to present | conf 0.95 | valid | [clm_B23CF82119F1](/claim/clm_B23CF82119F1.md)
  sources: https://x.ai/news/grok-4-fast

## Questions this record answers

### What is Grok 4 Fast's current context window?

2 M token, dated September 19, 2025, from a primary source (x.ai). The record asserts this claim as of November 4, 2026 (status valid, confidence 0.95).


## Get this data

- JSON: /v1/entities/grok-4-fast/context_window (this fact) · /v1/entities/grok-4-fast?predicates=context_window (with the entity's coverage; add as_of=YYYY-MM-DD for a date)
- MCP: timeline(entity: "grok-4-fast", predicates: ["context_window"]) for every dated value · fetch(id: "/record/grok-4-fast/context_window.md") for this page
- Entity twin: /record/grok-4-fast.md · timeline: /timelines/grok-4-fast.md

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AsOf is a temporal fact ledger: a structured, dated, sourced record of what is true and what changed, built for AI retrieval.