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Grok 4.1 Fast vs Kimi K2.5

Head to head on 24 shared benchmarks, with price, context window, and release dates.

Benchmark scores

45

evals · sort by any column, ⤢ to expand fullscreen

Model
Kimi K2.5

Moonshot AI

68.3%1576elo74.978.9%13.2%43.7%78.5%72.5%77.9%61.4%57.4%77.7%84.9%76.0%62.0%39.3%76.4%66.5%49.9%39.6%74.2%18.9%17.5%81.3%--96.139.0%35.8%27.9%-95.4-10421--87.1-63.3%-7367.3%70.8%69.426.3%56.8%
Grok 4.1 Fast

xAI

66.0%1324elo40.163.7%5.1%36.5%80.2%64.7%69.6%52.2%28.2%74.3%83.7%80.2%60.8%28.1%78.7%42.6%31.3%29.6%73.1%14.4%1.2%63.7%62.0%34.3%----11.8-35.0%-39.9%100.0%-74.3%-4.0%-----51.0%
2 / 2 models
AttributeGrok 4.1 Fast

xAI

Kimi K2.5

Moonshot AI

DescriptionGrok 4.1 Fast is an AI model from xAI.Kimi K2.5 is an AI model from Kimi.
FamilyGrokKimi
Params--
Open weightsclosedclosed
LicenseproprietaryModified MIT
Released19 Nov 202527 Jan 2026
Context-262,144
Input $/1M-$0.60
Output $/1M-$3.00
Cache read $/1M-$0.100
Cache write $/1M--
Speed0 tok/s0 tok/s
Latency0.00 s0.00 s
Modalitiestexttext, image
Providers--
PublisherxAIMoonshot AI
Reported scores
Infraresolutionbench80.2% (150 samples)
Agent Diff Bench62.0% (179 samples)
Medpt100.0% (15 samples)
Hanabi11.8 (15 samples)
SciCode29.6% (AA)

FAQ

Is Grok 4.1 Fast or Kimi K2.5 better?
Across the 24 benchmarks both models report on Sophon, Kimi K2.5 leads on 21 of them. Which one is "better" depends on the benchmark - the table above shows every shared score.
How do Grok 4.1 Fast and Kimi K2.5 compare on GPQA Diamond?
Grok 4.1 Fast scores 63.7% and Kimi K2.5 scores 78.9% on GPQA Diamond.
When were Grok 4.1 Fast and Kimi K2.5 released?
Grok 4.1 Fast was released 19 Nov 2025 by xAI. Kimi K2.5 was released 27 Jan 2026 by Moonshot AI.

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