Model comparison

Grok 4.5 vs Kimi K2.5 Instant

Grok 4.5 is the stronger model overall, scoring 55.0 to 43.6 on the Noometry Index.

Last verified . 18 shared benchmarks.

Grok 4.5 xAI

55.0

Rank #25 Confirmed

Kimi K2.5 Instant Moonshot AI

43.6

Rank #89 Confirmed

Summary

  • They share 18 benchmarks with published results for both. Grok 4.5 scores higher in 8 categories and Kimi K2.5 Instant in 1 category; 7 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Grok 4.5 leads 56.1 to 29.7.
  • Kimi K2.5 Instant has downloadable open weights; the other is API-only.

Side by side

Grok 4.5 and Kimi K2.5 Instant specifications
Grok 4.5Kimi K2.5 Instant
ProviderxAIMoonshot AI
Noometry Index55.043.6
Released2026-07-08—
WeightsProprietaryOpen
Context window500K—
Max output500K—
Input $ / M tokens$2—
Output $ / M tokens$6—
Results tracked5218

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Category by category

Coding Grok 4.5 leads

Grok 4.5: 52.2 (#35), Kimi K2.5 Instant: 42.6 (#97)

Coding benchmarks
BenchmarkGrok 4.5Kimi K2.5 Instant
LMArena WebDev15531404
LMArena Coding14741484
DeepSWE53.8%—
FrontierCode42.4%—
SciCode54.1%—
WeirdML46.4%—
ALE-Bench1,309—

Agentic & Tool Use Not comparable

Grok 4.5: 44.4 (#17), Kimi K2.5 Instant: —

Agentic & Tool Use benchmarks
BenchmarkGrok 4.5Kimi K2.5 Instant
APEX-Agents56.2%—
τ²-bench Banking47.9%—
PostTrainBench23.4%—
GBAEval65.4%—
GDP.pdf14%—
LMArena Search1213—
Vending-Bench 23,887—

Reasoning Grok 4.5 leads

Grok 4.5: 56.1 (#25), Kimi K2.5 Instant: 29.7 (#90)

Reasoning benchmarks
BenchmarkGrok 4.5Kimi K2.5 Instant
LMArena Hard Prompts14621443
ARC-AGI-252.6%—
SimpleBench70%—
Kagi LLM Benchmark83.5%—
NYT Connections (extended)79.9%—
ARC-AGI-187.2%—
CritPt15.4%—
Chess Puzzles36%—
DTBench96.5%—
LMCA45.2%—
Surface Evolver Bench74.4%—
Epoch Capabilities Index153.92—

Math Grok 4.5 leads

Grok 4.5: 60.9 (#35), Kimi K2.5 Instant: 39.4 (#105)

Math benchmarks
BenchmarkGrok 4.5Kimi K2.5 Instant
LMArena Math14591442
FrontierMath (Tiers 1-3)57.2%—
FrontierMath Tier 424.4%—
OTIS Mock AIME 2024-202597.8%—
ProofBench31%—

Knowledge Grok 4.5 leads

Grok 4.5: 62.3 (#24), Kimi K2.5 Instant: 40.2 (#123)

Knowledge benchmarks
BenchmarkGrok 4.5Kimi K2.5 Instant
LMArena Expert14661440
GPQA Diamond93.4%—
SimpleQA Verified48.3%—

Multimodal Kimi K2.5 Instant leads

Grok 4.5: 37.6 (#72), Kimi K2.5 Instant: 40.2 (#50)

Multimodal benchmarks
BenchmarkGrok 4.5Kimi K2.5 Instant
LMArena Vision12881254
Blueprint-Bench 227.3%—
Furniture Assembly22.5%—
LMArena Document1452—

Multilingual Grok 4.5 leads

Grok 4.5: 54.4 (#42), Kimi K2.5 Instant: 52.0 (#94)

Multilingual benchmarks
BenchmarkGrok 4.5Kimi K2.5 Instant
LMArena Non-English14401406
LMArena Chinese14961449
LMArena French14561403
LMArena German14461413
LMArena Korean14041378
LMArena Russian14481404
LMArena Spanish14501447
LMArena Japanese1428—

Instruction Following Too close to call

Grok 4.5: 76.0 (#48), Kimi K2.5 Instant: 75.3 (#65)

Instruction Following benchmarks
BenchmarkGrok 4.5Kimi K2.5 Instant
LMArena Instruction Following14461430

Long Context Too close to call

Grok 4.5: 44.8 (#56), Kimi K2.5 Instant: 43.9 (#83)

Long Context benchmarks
BenchmarkGrok 4.5Kimi K2.5 Instant
LMArena Longer Query14631435

Writing & Preference Grok 4.5 leads

Grok 4.5: 65.8 (#42), Kimi K2.5 Instant: 60.6 (#95)

Writing & Preference benchmarks
BenchmarkGrok 4.5Kimi K2.5 Instant
LMArena Text14481420
LMArena Creative Writing14421381
LMArena Multi-Turn14561427
EQ-Bench Creative Writing1579—

Frequently asked questions

Is Grok 4.5 better than Kimi K2.5 Instant?

Grok 4.5 is the stronger model overall, scoring 55.0 to 43.6 on the Noometry Index.

Is Grok 4.5 or Kimi K2.5 Instant better for coding?

Grok 4.5 scores higher on coding benchmarks: 52.2 versus 42.6 in the Noometry coding category.

How many benchmarks do Grok 4.5 and Kimi K2.5 Instant share?

18 benchmarks have published results for both models. Grok 4.5 has 52 scored results on Noometry and Kimi K2.5 Instant has 18.

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