Noometry

Model comparison

Grok 4 vs Kimi K2.5 Instant

Grok 4 is the stronger model overall, scoring 47.8 to 42.9 on the Noometry Index.

Last verified . 17 shared benchmarks.

Grok 4 xAI

47.8

Rank #49 Confirmed

Kimi K2.5 Instant Moonshot AI

42.9

Rank #92 Confirmed

Summary

  • They share 17 benchmarks with published results for both. Grok 4 scores higher in 6 categories and Kimi K2.5 Instant in 3 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in long context, where Grok 4 leads 63.1 to 43.8.
  • Kimi K2.5 Instant has downloadable open weights; the other is API-only.

Side by side

Grok 4Kimi K2.5 Instant
ProviderxAIMoonshot AI
Noometry Index47.842.9
Released2025-07-09—
WeightsProprietaryOpen
Context window——
Max output——
Input $ / M tokens——
Output $ / M tokens——
Results tracked4818

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Category by category

Coding Grok 4 leads

Grok 4: 49.9 (#44), Kimi K2.5 Instant: 42.3 (#95)

BenchmarkGrok 4Kimi K2.5 Instant
LMArena Coding14081483
Aider Polyglot79.6%—
LMArena WebDev—1404
WeirdML45.7%—

Agentic & Tool Use Not comparable

Grok 4: 32.1 (#62), Kimi K2.5 Instant: —

BenchmarkGrok 4Kimi K2.5 Instant
Terminal-Bench27.2%—
Berkeley Function Calling Leaderboard63%—
GDPval21.1%—
Cybench43%—
DeepResearch Bench47.3%—
BALROG43.6%—
LMArena Search1142—
METR Time Horizons66.6%—

Reasoning Grok 4 leads

Grok 4: 36.9 (#59), Kimi K2.5 Instant: 28.5 (#88)

BenchmarkGrok 4Kimi K2.5 Instant
LMArena Hard Prompts14091443
ARC-AGI-216%—
SimpleBench60.5%—
Kagi LLM Benchmark73.6%—
ARC-AGI-166.7%—
Chess Puzzles28%—
Epoch Capabilities Index146.46—
ForecastBench60.9—

Math Grok 4 leads

Grok 4: 46.5 (#58), Kimi K2.5 Instant: 36.6 (#105)

BenchmarkGrok 4Kimi K2.5 Instant
LMArena Math14221443
OTIS Mock AIME 2024-202584%—
Omni-MATH60.3%—
FrontierMath (Feb 2025 set)19.7%—
FrontierMath Tier 4 (v1)2.1%—

Knowledge Grok 4 leads

Grok 4: 53.7 (#50), Kimi K2.5 Instant: 39.5 (#121)

BenchmarkGrok 4Kimi K2.5 Instant
LMArena Expert14171438
GPQA Diamond87%—
MMLU-Pro85.1%—
Confabulations12.4%—
GPQA (HELM)72.7%—

Multimodal Kimi K2.5 Instant leads

Grok 4: 33.1 (#89), Kimi K2.5 Instant: 39.5 (#47)

BenchmarkGrok 4Kimi K2.5 Instant
LMArena Vision12111254
GeoBench45%—

Multilingual Too close to call

Grok 4: 52.0 (#98), Kimi K2.5 Instant: 52.2 (#89)

BenchmarkGrok 4Kimi K2.5 Instant
LMArena Non-English14031406
LMArena Chinese14281450
LMArena French14181403
LMArena German14291413
LMArena Korean13761378
LMArena Russian14091404
LMArena Spanish14191448
LMArena Japanese1396—

Instruction Following Grok 4 leads

Grok 4: 79.4 (#4), Kimi K2.5 Instant: 75.5 (#61)

BenchmarkGrok 4Kimi K2.5 Instant
LMArena Instruction Following13871430
IFEval94.9%—

Long Context Grok 4 leads

Grok 4: 63.1 (#4), Kimi K2.5 Instant: 43.8 (#82)

BenchmarkGrok 4Kimi K2.5 Instant
LMArena Longer Query14091435
Fiction.LiveBench94.4%—

Writing & Preference Kimi K2.5 Instant leads

Grok 4: 58.7 (#111), Kimi K2.5 Instant: 60.8 (#91)

BenchmarkGrok 4Kimi K2.5 Instant
LMArena Text14121420
LMArena Creative Writing13971379
LMArena Multi-Turn14161427
Short-Story Creative Writing76.9%—
WildBench79.7%—

Frequently asked questions

Is Grok 4 better than Kimi K2.5 Instant?

Grok 4 is the stronger model overall, scoring 47.8 to 42.9 on the Noometry Index.

Is Grok 4 or Kimi K2.5 Instant better for coding?

Grok 4 scores higher on coding benchmarks: 49.9 versus 42.3 in the Noometry coding category.

How many benchmarks do Grok 4 and Kimi K2.5 Instant share?

17 benchmarks have published results for both models. Grok 4 has 48 scored results on Noometry and Kimi K2.5 Instant has 18.

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