Grok 4.1 Fast (Reasoning)

Grok 4.1 Fast (Reasoning) is one of two configurations in the Grok 4.1 Fast family released by xAI in November 2025, sitting alongside a non-reasoning sibling. It is positioned as a speed- and cost-oriented model that still supports explicit chain-of-thought reasoning, with Artificial Analysis reporting text-and-image inputs, text output, and a two-million-token context window. Within the family, Artificial Analysis's Intelligence Index v4.3.2 ranks the reasoning variant meaningfully above its non-reasoning counterpart, reflecting the boost that the reasoning mode brings to tasks requiring multi-step planning or tool use.

On independent benchmarks, the reasoning variant reaches an Artificial Analysis Intelligence Index of 20, ahead of the non-reasoning sibling's 11, and tracks competitively on coding-oriented work: third-party catalog BenchLM gives it a capability score of 54.82 out of 100, a 92-of-230 overall rank, and a coding sub-rank of 89, suggesting a practical fit for software engineering and agentic coding workloads where it can trade extra tokens for more reliable problem solving. The model's combination of a very large context window and image input also makes it usable for long-document analysis and visually grounded tasks, while the reasoning mode adds latency and token usage that callers need to plan for in production.

FrogBotgrok-4-1-fast-reasoninggrok

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Quick Info

Provider: FrogBot
Model key: grok-4-1-fast-reasoning
Release date: Nov 25, 2025
Last updated: Nov 25, 2025
Knowledge cutoff: 2025-11
Input modalities
Output modalities
Capabilities

Cost

Input token cost: $0.20
Output token cost: $0.50

Limits

Output tokens: 128,000 tokens
Context window: 2,000,000 tokens

Transparent token rates

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Rates are shown per one million tokens. Combined means one million input plus one million output tokens.

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Latest news about Grok 4.1 Fast (Reasoning)

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CoverageBenchmark

Analysis of xAI's Grok 4.1 Fast (Reasoning) and comparison to other AI models across key metrics including quality, price, performance (tokens per second & time to first token), context window & more.

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CoverageRelease Notes

Artificial Analysis's Spanish-language release page for Grok 4.1 Fast (November 2025, SpaceXAI/xAI proprietary) compares the two sibling variants head-to-head: Grok 4.1 Fast (Reasoning) leads on intelligence with an Artificial Analysis Intelligence Index score of 20, while Grok 4.1 Fast (Non-reasoning) scores 11. Techn The Intelligence Index is v4.3.2, composed of 10 evaluations (AA-Briefcase v1.1, GDPval-AA v2.1, AutomationBench-AA, Terminal-Bench 4.0, SciCode, Humanity's Last Exam, GDP.pdf, CritPt, AA-Omniscience, AA-LCR v1.1), placing the reasoning variant at rank 28 of 673 models with cost-per-task and intelligence-vs-cost scatte

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CoverageBenchmark

BenchLM's model card for Grok 4.1 Fast (Reasoning) records an overall Capability score of 54.8/100 (rank 92 of 230 ranked models) with creator attribution to xAI, and reports a 2M-token context window. The model lands at rank 89 of 154 on Coding (42nd percentile) with a verified benchmark score of 46.0. Input and outpu Evidence coverage is sparse: only one verified benchmark row (coding) is on file, while Agentic, Reasoning, Knowledge, Math, Multilingual, Multimodal, and Instruction Following are all marked Not measured, so capability claims should be treated as directional rather than authoritative. The page is useful as a developer