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xAI · Grok
No. 17
Grok 4.1 Fast
Cheap, fast, 2M-context workhorse for high throughput.
Field notes
- Context window
- 2Mtokens
- Max output
- 66Ktokens
- Input price
- $0.20/ 1M tokens
- Output price
- $0.50/ 1M tokens
- Cached input
- $0.05/ 1M tokens
- Modalities
- Text, Image
- Knowledge cutoff
- May 2025
- Released
- Nov 2025
- Approx. speed
- ~250 tok/s
Overview
What this model is
Grok 4.1 Fast is xAI's high-throughput, low-cost tier with a 2M-token context window and aggressive prompt-cache pricing. It is great value for search, summarization, and high-volume calls with real-time data access. It trades away reliability on complex reasoning and multi-step coding, so it is best as a fast utility model rather than an autonomous coding agent.
Strengths
- Very low cost with cheap prompt caching
- Huge 2M-token context window
- Fast response latency
- Real-time X/web data access
Trade-offs
- Weaker on complex coding and agentic tasks
- Lower reasoning depth than the flagship
- Less consistent tool use
- Shallower on hard STEM problems
Best for
- High-volume, low-cost inference
- Retrieval and summarization
- Real-time search over large context
- Simple classification and extraction
Not ideal for
- Complex multi-file coding
- Long-horizon agentic automation
Capabilities
Capability profile
Normalized 0–100 scores, comparable across the whole catalog.
- Reasoning
- 74
- Coding
- 68
- Math
- 80
- Writing
- 76
- Knowledge
- 80
- Speed
- 92
- Agentic
- 66
- Vision
- 74
- Multilingual
- 76
- Long Context
- 85
Benchmarks
How it scores
Public benchmark results, with independent third-party results where available. Bars normalize percentages to 100 and Elo ratings to a 1500 ceiling.
Independent index
Artificial Analysis Intelligence Index
Composite of ~9–10 independent evals · Artificial Analysis
31/ 100
BenchmarkResult
Artificial Analysis Intelligence Indexindependent
GeneralArtificial Analysis
31%
τ-benchindependent
Agenticτ-bench
72.8%