Grok 4 Fast

Name: Grok 4 Fast
Author: xAI

GrokvFastDeprecated

xAI(ai lab)

Released September 19, 2025

Deprecated May 15, 2026

Run this model yourself API Docs Playground

Context2M tokens

Price (In / Out)$0.20/M / $0.50/M

CategoryMultimodal LLM

Max Output30K tokens

About Grok 4 Fast

Grok 4 Fast is a multimodal llm from xAI. Supports up to 2,000,000 token context window. Available from $0.20/M input tokens.

Capabilities

textvisioncode

Input Modalities

textimagefile

Output Modalities

text

Technical Details

API Identifier: x-ai/grok-4-fast
Category: Multimodal LLM
Context Window: 2,000,000 tokens
Max Output Tokens: 30,000 tokens

Run this model yourself

Local and cloud setup for Grok 4 Fast, with exact configurations, sources and clear evidence limits.

Find a model for your hardware

No reviewed setup guide is available for this model yet. Explore configurations with documented support in the hardware finder.

Benchmarks

Performance scores for Grok 4 Fast across standard benchmarks.

GPQA DiamondArtificial Analysis

60.6%

AIME 2025Artificial Analysis

41.3%

Pricing

Token pricing for Grok 4 Fast API usage.

Input Tokens

$0.20/M

per million tokens

Output Tokens

$0.50/M

per million tokens

Cache read: $0.0500/M tokens

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Model	Context Window	Price (In / Out per M)	Capabilities
Grok 4.7Current	500K	$2.00 / $6.00	codingreasoningvisiontool use+3
Grok 4.20 Multi-AgentCurrent	2.0M	$2.00 / $6.00	textvisioncode
Grok 4.20Current	2.0M	$2.00 / $6.00	textvisioncode
Grok 4.1 FastDeprecated	2.0M	Deprecated	textvisioncode