Grok 4.1 Fast (Reasoning)

Grok 4.1 Fast (Reasoning)

Developer	xAI
Release date	November 19, 2025
Family	Grok
Generation	Grok 4.1
Level
Context window	2M tokens
Max output	30K tokens
Input	Text, image
Output	Text
Weights	Closed
Predecessor	X-Ai/Grok-4-Fast-Reasoning
Website	x.ai

Part of a series on

Context: 2Mtokens
Released: 11mo ago

Specifications

Model

Developer: xAI
Family: Grok Grok 4.1
Type: Language model
Released: November 19, 2025
Model ID: xai/grok-4.1-fast-reasoning

Capabilities

Input → output: Text, image → Text
Max output: 30K tokens

Weights

Openness: Closed

Sources:models.dev

Metadata synced Nov 11, 2026, 10:02 AM UTC

To give you the best experience, we use cookies for personalization, insights, and performance. Learn more.