#18
Grok 4 Fast
grok-4-fast-non-reasoning

Grok 4 Fast Non-Reasoning is a lightweight variant of Grok 4 Fast optimized for low-latency everyday workloads where step-by-step reasoning traces are not required. It keeps the same large 2M-token context window and strong general capabilities but trims some of the deepest reasoning and comprehension capacity in exchange for very high responsiveness and low cost. This makes it well suited for classification, summarization, routing, and high-traffic chat experiences that still benefit from modern model quality without paying for full frontier-level thinking.

Performance Metrics

Helpfulness
Instruction Following
Comprehension
Empathy
Creative Writing
85.20
Helpfulness
87
Empathy
86
Instruction Following
89
Creative Writing
75.5
Comprehension
88.5
Speed
Avg 93 tok/s

Model Specifications

Release Date
September 19, 2025
Lab
xAI
Type
Proprietary
Context Size
2M
Max Output Tokens
8.2K
Cost per 1M tokens
$0.20 / $0.50
Model Inputs
Text, Images, Code, Web
Model Outputs
Text
Tool Calling
Enabled

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