[whatmodel.sh](../../README.md) / Grok 4.1 Fast (Reasoning)
# Grok 4.1 Fast (Reasoning)
SpaceXAI (xAI) · released 2025-11 · closed weights
**score 65.6** ±1.0 · #136 of 732 · from 15 benchmark results across 10 sources
Score within the [LMArena (text)](https://whatmodel.sh/?set=lmarena-text&score=set) comparison set only.
## What it's good at
● marks Grok 4.1 Fast (Reasoning) among every model on that task or test, worst to best.
task vs the others rank counts tests
agent tasks ▁▁▃▆█▄●▅▄▄▂▁ #118 of 313 16% 4
coding ▁▁▁▃▅▇█●▅▄▃▁ #174 of 469 29% 3
chat & writing ▁▁▁▃▆▄▆█▆●▇▃ #82 of 402* 11% 1
math ▁▁▃▅█▆▄●▄▂▁▁ #94 of 431 29% 4
vision & documents ▁▁▂▂▁▃▄▂●▇█▄ #84 of 153* 7.3% 1
web search ▁▁▁▅▄●▃▄·▁·▁ #38 of 84* 4.0% 1
agent tasks · #118 of 313 · 16% of its score
Beats [o3-pro](o3-pro.md), [Grok 4.3](grok-4-3.md), [Qwen3.6 Plus](qwen3-6-plus.md) here, though they rank higher overall. Trails [SmolLM3 3B](smollm3-3b.md), [Jamba 1.5 Large](jamba-1-5-large.md), [Devstral 2 (2512)](devstral-2.md) here, though they rank lower overall.
test result vs the others in its run difficulty counts why
BFCL V4 (December 2025 archive) 69.6% ▁▁▁▂██▅▅▆▂●▂ beats 74/77 hard · avg 31% 5.3% at its level
τ³-bench banking_knowledge (v1.0.… 13.1% ▃●▂▃·▆▃▂█▅▅▂ beats 2/25 very hard · avg 4.3% 5.0% typical
Vibe Code Bench (test split, 50 w… 1.2% ●··▃·▃██▃▃▃█ beats 0/14 very hard · avg 2.8% 3.3% sharp · noisy
τ²-Bench-Verified (GPT-5.1 user) 82.7% ▂··▄···▂▄▄█● beats 13/13 medium · avg 45% 1.9% at its level
coding · #174 of 469 · 29% of its score
Beats [Qwen3-Coder-Next (80B-A3B)](qwen3-coder-next.md), [Gemini 2.5 Pro](gemini-2-5-pro.md) here, though they rank higher overall. Trails [QwQ-32B-Preview](qwq-32b-preview.md), [Ministral 3 8B Reasoning 2512](ministral-3-8b-reasoning.md), [Phi-4-reasoning 14B](phi-4-reasoning.md) here, though they rank lower overall.
test result vs the others in its run difficulty counts why
Arena WebDev (Code Arena) 1242.1 ▁▁●▂▅█▃▆▅▅▁▂ beats 10/129 avg 981 19% sharp
WebApp1K-Duo-React pass@1 (onekq-… 71.6% ▁··▁·▁▁▁▆█●█ beats 33/45 hard · avg 29% 5.8% at its level
Vibe Code Bench (test split, 50 w… 1.2% ●··▃·▃██▃▃▃█ beats 0/14 very hard · avg 2.8% 3.3% sharp · noisy
chat & writing · #82 of 402 · 11% of its score
Beats [Claude Haiku 5.5](claude-haiku-5-5.md), [LongCat 2.0 (1.6T-A48B)](longcat-2-0.md), [Muse Glimmer 30B](muse-glimmer-30b.md) here, though they rank higher overall. Trails [Gemma 4 12B](gemma-4-12b.md), [Gemma 4 26B-A4B](gemma-4-26b-a4b.md), [Nemotron Cascade 2 30B-A3B](nemotron-cascade-2-30b-a3b.md) here, though they rank lower overall.
test result vs the others in its run difficulty counts why
LMArena (text) 1430.3 ▁▁▁▂▃▃▃▆▆●█▃ beats 286/385 avg 1260 11% blunt
math · #94 of 431 · 29% of its score
Beats [Claude Sonnet 4.6](claude-sonnet-4-6.md), [Claude Opus 4.5](claude-opus-4-5.md), [MiniMax-M3](minimax-m3.md) here, though they rank higher overall. Trails [Gemini 2.5 Flash](gemini-2-5-flash.md), [Granite 4.2 30B](granite-4-2-30b.md), [Qwen3-Next 80B-A3B Instruct](qwen3-next-80b-a3b-instruct.md) here, though they rank lower overall.
test result vs the others in its run difficulty counts why
MathArena ArXivMath February 2026… 32.0% ▁▁▁▁●▇▄▃▁▃·▃ beats 8/24 very hard · avg 9.4% 12% at its level
MathArena ArXivMath January 2026 … 53.3% ▂··▄▂▄●▆▆▄▄█ beats 8/23 hard · avg 23% 9.5% at its level
MathArena ArXivMath December 2025… 50.0% ▃·▃▃█▁·●·▁▁▁ beats 13/18 hard · avg 19% 6.2% at its level
FormalProofBench (200 graduate-le… 4.0% ▃●·▃··▅▃█··▃ beats 1/10 very hard · avg 3.1% 1.5% noisy
vision & documents · #84 of 153 · 7.3% of its score
Beats [DeepSeek V4 Flash Vision (Exp)](deepseek-v4-flash-vision-exp.md), [GPT-5.4 nano](gpt-5-4-nano.md), [GPT-5 mini](gpt-5-mini.md) here, though they rank higher overall. Trails [GPT-4.1 mini](gpt-4-1-mini.md), [Gemini 2.5 Flash](gemini-2-5-flash.md), [Gemma 4 12B](gemma-4-12b.md) here, though they rank lower overall.
test result vs the others in its run difficulty counts why
Arena vision (style controlled) 1196.3 ▁▁▂▂▂▂▃▄●▅█▇ beats 70/152 avg 1061 7.3% blunt
web search · #38 of 84 · 4.0% of its score
Beats [Gemini 3.1 Pro (Preview)](gemini-3-1-pro.md), [Gemini 3.5 Flash](gemini-3-5-flash.md), [Qwen3.7 Max](qwen3-7-max.md) here, though they rank higher overall. Trails [GPT-4o mini (2024-07-18)](gpt-4o-mini-2024-07-18.md), [Mistral Small 3.1 24B (2503)](mistral-small-3-1.md), [Llama 4 Scout (109B-A17B)](llama-4-scout.md) here, though they rank lower overall.
test result vs the others in its run difficulty counts why
Arena search systems (style contr… 1195.0 ▁·▁▁▂▂▂●▆▃▂▂ beats 17/36 avg 1069 4.0% blunt
other tests (2)
test result vs the others in its run difficulty counts why
KINA (Knowledge Index of Noah's A… 33.7% ▁▁▂▁▃▄█▆●▅▂▃ beats 26/39 very hard · avg 21% 7.7% at its level
Vectara hallucination leaderboard… 80.8% ▁●▁▂▅█▂▃▄▃▁▁ beats 6/98 very easy · avg 90% 0.0% blunt
source results share of the score
LMArena leaderboard dataset 4 42% ▇▇▇▇▇
MathArena ArXivMath / BrokenArXiv / ArX… 3 27% ▇▇▇
Knowledge Index of Noah's Ark 1 8% ▇
WebApp1K models leaderboard 1 6% ▇
Berkeley Function Calling Leaderboard r… 1 5% ▇
τ²/τ³-bench leaderboard: Sierra's own e… 1 5% ▇
Vibe Code Bench 1 3% ▇
Amazon AGI 1 2% ▇
FormalProofBench 1 1% ▇
Vectara hallucination leaderboard 1 0% ▇
prior: pull toward the middle 0% ▇
weighted average = 65.6
Licences: LMArena leaderboard dataset ([CC BY 4.0](https://creativecommons.org/licenses/by/4.0/)) · MathArena ArXivMath / BrokenArXiv / ArXivLean model-output datasets ([CC BY-SA 4.0](../../licenses/matharena-sharealike-NOTICE.txt)) · Knowledge Index of Noah's Ark ([CC BY 4.0](https://creativecommons.org/licenses/by/4.0/)) · WebApp1K models leaderboard ([MIT](../../licenses/webapp1k-leaderboard-MIT.txt)) · Berkeley Function Calling Leaderboard result archive ([Apache-2.0](../../licenses/bfcl-result-archive-v4-Apache-2.0.txt)) · τ²/τ³-bench leaderboard: Sierra's own evaluation runs ([MIT](https://opensource.org/license/mit)) · Vibe Code Bench ([CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/)) · Amazon AGI ([MIT](../../licenses/tau2-verified-MIT.txt)) · FormalProofBench ([CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/)) · Vectara hallucination leaderboard ([Apache-2.0](https://www.apache.org/licenses/LICENSE-2.0))
## How to run it
### Through an API
api (Microsoft Azure) · $0.28/M blended · $0.2 in / $0.5 out per 1M tokens · [azure.microsoft.com](https://azure.microsoft.com/en-us/pricing/details/ai-foundry-models/grok)
[price source](https://azure.microsoft.com/en-us/pricing/details/ai-foundry-models/grok): USD per 1M tokens, Azure AI Foundry Models pay-as-you-go (xAI Grok table), 'Grok 4.1 Fast Global': input $0.20, output $0.50, region US East. The Azure model id is grok-4-1-fast-reasoning, version 1, GA, with no retirement date on Azure's schedule; the same row covers grok-4-1-fast-non-reasoning. Azure lists a 128,000-token input limit for this deployment. xAI's own price table no longer lists grok-4-1-fast-reasoning, and Google Cloud shut its Vertex endpoint down on 2026-08-20. Currency: USD. Microsoft Azure official pricing page (price cells carry the amounts in the page's own data), observed 2026-09-26. · [context source](https://learn.microsoft.com/en-us/azure/foundry/foundry-models/concepts/models-sold-directly-by-azure): Context limit from the maker's documentation, observed 2026-10-06.
[interactive version](https://whatmodel.sh/model/grok-4-1-fast-reasoning) · [JSON](https://whatmodel.sh/api?format=json&all=1)