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xAI
Grok 4 Fast

Grok 4 Fast is xAI's latest multimodal model with SOTA cost-efficiency and a 2M token context window. It comes in two flavors: non-reasoning and reasoning. Read more about the model on xAI's news post.

Reasoning can be enabled/disabled using the reasoning enabled parameter in the API. Learn more in our docs

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Model details

Context window2,000,000 tokens
Max completion size82 tokens
Prompt cost / 1K tokens$0.0000002
Completion cost / 1K tokens$0.0000005
Accepts
Produces

Benchmark performance

Overall

88
score
1st
placement

Cost

98
score
3rd
placement

Logic

91
score
2nd
placement

Speed

86
score
14th
placement

Scoring

38
score
12th
placement

Tool Use

64
score
2nd
placement

Hallucination

83
score
7th
placement

Classification

50
score
1st
placement

Structured Output

100
score
1st
placement

Pricing

Usage pricing
Prompt$0.0000002
Completion$0.0000005
RequestFREE
ImageFREE
Web Search$0.010
Internal ReasoningFREE
Input Cache ReadFREE
Input Cache WriteFREE

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