Noometry

Model comparison

Grok 4.20 (Non-Reasoning) vs Kimi K2 (Jul 2025)

Grok 4.20 (Non-Reasoning) is the stronger model overall, scoring 48.6 to 41.2 on the Noometry Index. Kimi K2 (Jul 2025) costs 1.6× less per token, which makes it the better buy when Grok 4.20 (Non-Reasoning)'s lead doesn't matter for your workload.

Last verified . 25 shared benchmarks.

Grok 4.20 (Non-Reasoning) xAI

48.6

Rank #54 Confirmed

Kimi K2 (Jul 2025) Moonshot AI

41.2

Rank #140 Confirmed

Summary

  • They share 25 benchmarks with published results for both. Grok 4.20 (Non-Reasoning) scores higher in 8 categories and Kimi K2 (Jul 2025) in 1 category; 8 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Grok 4.20 (Non-Reasoning) leads 52.3 to 23.3.
  • The biggest single-benchmark swing is Terminal-Bench: 57.3% for Grok 4.20 (Non-Reasoning) and 35.7% for Kimi K2 (Jul 2025).
  • Kimi K2 (Jul 2025) is cheaper at $0.57 / $2.30 per million input/output tokens, against $1.25 / $2.50 for Grok 4.20 (Non-Reasoning).
  • Grok 4.20 (Non-Reasoning) accepts more context: 1M tokens versus 262K.
  • Kimi K2 (Jul 2025) has downloadable open weights; the other is API-only.

Side by side

Grok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
ProviderxAIMoonshot AI
Noometry Index48.641.2
Released2026-02-172025-07-12
WeightsProprietaryOpen
Context window1M262K
Max output30K262K
Input $ / M tokens$1.25$0.57
Output $ / M tokens$2.50$2.30
Results tracked4642

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Category by category

Coding Too close to call

Grok 4.20 (Non-Reasoning): 42.1 (#112), Kimi K2 (Jul 2025): 42.4 (#102)

BenchmarkGrok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
WeirdML52.3%42.8%
LMArena Coding14591399
ALE-Bench1,150597.5
SWE-bench Verified (bash only)—63.4%
Aider Polyglot—59.1%
LMArena WebDev1375—
GSO—4.9%

Agentic & Tool Use Grok 4.20 (Non-Reasoning) leads

Grok 4.20 (Non-Reasoning): 34.4 (#46), Kimi K2 (Jul 2025): 32.4 (#64)

BenchmarkGrok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
Terminal-Bench57.3%35.7%
Berkeley Function Calling Leaderboard—59.1%
τ²-bench Banking18%—
LMArena Search1189—
METR Time Horizons—59.2%
Vending-Bench 24,663—

Reasoning Grok 4.20 (Non-Reasoning) leads

Grok 4.20 (Non-Reasoning): 52.3 (#32), Kimi K2 (Jul 2025): 23.3 (#179)

BenchmarkGrok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
Kagi LLM Benchmark75%64.4%
LMArena Hard Prompts14511384
Epoch Capabilities Index151.98146.01
ForecastBench61.460.2
ARC-AGI-265.1%—
SimpleBench—26.3%
NYT Connections (extended)85.4%—
ARC-AGI-189.5%—
Chess Puzzles24%—
Thematic Generalization63.8%—
DTBench90.1%—
LMCA38.7%—

Math Grok 4.20 (Non-Reasoning) leads

Grok 4.20 (Non-Reasoning): 48.2 (#65), Kimi K2 (Jul 2025): 42.7 (#83)

BenchmarkGrok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
LMArena Math14551397
FrontierMath (Tiers 1-3)44.9%—
FrontierMath Tier 417.1%—
OTIS Mock AIME 2024-202592.2%—
ProofBench14%—
Omni-MATH—65.4%
FrontierMath (Feb 2025 set)—21.4%
FrontierMath Tier 4 (v1)—0%

Knowledge Grok 4.20 (Non-Reasoning) leads

Grok 4.20 (Non-Reasoning): 52.8 (#60), Kimi K2 (Jul 2025): 37.3 (#157)

BenchmarkGrok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
LMArena Expert14391365
GPQA Diamond89.3%—
SimpleQA Verified30.2%—
MMLU-Pro—81.9%
Confabulations—20.4%
Vectara Hallucination Rate—17.9%
GPQA (HELM)—65.3%

Multimodal Not comparable

Grok 4.20 (Non-Reasoning): 33.3 (#98), Kimi K2 (Jul 2025): —

BenchmarkGrok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
LMArena Vision1263—
Blueprint-Bench 20%—
LMArena Document1416—

Multilingual Grok 4.20 (Non-Reasoning) leads

Grok 4.20 (Non-Reasoning): 54.5 (#40), Kimi K2 (Jul 2025): 49.6 (#130)

BenchmarkGrok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
LMArena Non-English14411372
LMArena Chinese14811415
LMArena French14761379
LMArena German14651387
LMArena Japanese14491349
LMArena Korean14171325
LMArena Russian14581385
LMArena Spanish14431386

Instruction Following Grok 4.20 (Non-Reasoning) leads

Grok 4.20 (Non-Reasoning): 74.8 (#83), Kimi K2 (Jul 2025): 71.1 (#156)

BenchmarkGrok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
LMArena Instruction Following14201348
IFEval—85%

Long Context Grok 4.20 (Non-Reasoning) leads

Grok 4.20 (Non-Reasoning): 45.5 (#34), Kimi K2 (Jul 2025): 41.2 (#145)

BenchmarkGrok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
CL-bench22.2%17.6%
LMArena Longer Query14371353
Fiction.LiveBench—66.7%
CL-bench Life11.9%—

Writing & Preference Grok 4.20 (Non-Reasoning) leads

Grok 4.20 (Non-Reasoning): 65.7 (#44), Kimi K2 (Jul 2025): 62.3 (#78)

BenchmarkGrok 4.20 (Non-Reasoning)Kimi K2 (Jul 2025)
LMArena Text14511380
LMArena Creative Writing14381350
EQ-Bench Creative Writing15741666
LMArena Multi-Turn14561371
Short-Story Creative Writing—85.6%
WildBench—86.2%

Frequently asked questions

Is Grok 4.20 (Non-Reasoning) better than Kimi K2 (Jul 2025)?

Grok 4.20 (Non-Reasoning) is the stronger model overall, scoring 48.6 to 41.2 on the Noometry Index. Kimi K2 (Jul 2025) costs 1.6× less per token, which makes it the better buy when Grok 4.20 (Non-Reasoning)'s lead doesn't matter for your workload.

Which is cheaper, Grok 4.20 (Non-Reasoning) or Kimi K2 (Jul 2025)?

Kimi K2 (Jul 2025) is cheaper. It lists at $0.57 per million input tokens and $2.30 per million output tokens; Grok 4.20 (Non-Reasoning) lists at $1.25 and $2.50.

Is Grok 4.20 (Non-Reasoning) or Kimi K2 (Jul 2025) better for coding?

They score almost the same on coding (42.1 vs 42.4); test both on your own repository before choosing.

Which has the bigger context window?

Grok 4.20 (Non-Reasoning) does, with 1M tokens against 262K.

How many benchmarks do Grok 4.20 (Non-Reasoning) and Kimi K2 (Jul 2025) share?

25 benchmarks have published results for both models. Grok 4.20 (Non-Reasoning) has 46 scored results on Noometry and Kimi K2 (Jul 2025) has 42.

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