Grok 4.1 Fast
xAI's efficiency model. Long-context specialist with 2M window.
Scores by test
Methodology →What you need to know
Grok 4.1 Fast differentiates itself through high-reliability execution in structured tasks and massive context handling. With a 2M token window and perfect scores in structured output, persona consistency, and faithfulness, the model is built for complex, long-form data processing where adherence to specific formats and identities is critical.
At a blended cost of $0.425/MTok, the model is priced competitively for its capabilities. It provides high-tier performance in strategic analysis and multilingual tasks without the premium pricing typically associated with top-ranked frontier models, though its overall rank of 39 out of 71 suggests it is a specialized tool rather than a general-purpose leader.
The model has a significant failure point in safety calibration, scoring 1/5, meaning it lacks the guardrails found in most commercial models. It also shows relative weakness in tabular data processing, making it less suitable for spreadsheet-style analysis compared to its strength in textual structured output.
Use this model if you require a high-context window for large document analysis or need strict adherence to a specific persona and output schema. Skip this model if your application requires strict safety filtering or heavy manipulation of tabular data.
Strengths — Top 3
Relative weaknesses — Bottom 3
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