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Model comparison

Claude Opus 4.5 vs Kimi K2

Data verified

Head-to-head evidence from 14 shared benchmark results across 7 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

64.22/100
Margin
37.0pts
← winning
Kimi K2
Moonshot AI
27.19/100
1 category wins0 category wins

Public leaderboard positions: Claude Opus 4.5 #34 (Supported); Kimi K2 #189 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Opus 4.5 and Kimi K2 share 14 comparable benchmark results. 1 of 8 categories are comparable. 45 results are unique to Claude Opus 4.5; 0 to Kimi K2.

Updated July 22, 2026
Shared results
14
Claude Opus 4.5 only
45
Kimi K2 only
0
Comparable categories
1 / 8

Pick Claude Opus 4.5 if you want the stronger benchmark profile. Kimi K2 only becomes the better choice if you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 14 shared benchmark results across 7 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Opus 4.5 is clearly ahead on the BenchAlign aggregate, 64.22 to 27.19. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Opus 4.5's sharpest advantage is in mathematics, where it averages 57.5 against 16.1. The single biggest benchmark swing on the page is FrontierMath v2 (Tier 4), 4.167% to 0.000%.

Claude Opus 4.5 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $0.60 input / $2.50 output per 1M tokens for Kimi K2. That is roughly 10.0x on output cost alone. Claude Opus 4.5 gives you the larger context window at 200K, compared with 128K for Kimi K2.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Claude Opus 4.5 and Kimi K2
CategoryClaude Opus 4.5ΔKimi K2
MathClaude Opus 4.557.5Margin← 41.4Kimi K216.1
AgenticClaude Opus 4.562.6MarginNo overlapKimi K2Not measured
CodingClaude Opus 4.571.7MarginNo overlapKimi K2Not measured
ReasoningClaude Opus 4.564.4MarginNo overlapKimi K2Not measured
KnowledgeClaude Opus 4.558.1MarginNo overlapKimi K2Not measured
MultilingualClaude Opus 4.585.7MarginNo overlapKimi K2Not measured
MultimodalClaude Opus 4.569.9MarginNo overlapKimi K2Not measured
Inst. FollowingClaude Opus 4.569.5MarginNo overlapKimi K2Not measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Claude Opus 4.5B · Kimi K2

  1. FrontierMath v2 (Tier 4)

    Math
    Source ↗
    A 4.167%B 0.000%
    Winner: Claude Opus 4.5Δ 4.2
    FrontierMath v2 (Tier 4): Claude Opus 4.5 scored 4.167%; Kimi K2 scored 0.000%. Claude Opus 4.5 wins this benchmark.

  2. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 20.690%B 21.404%
    Winner: Kimi K2Δ 0.7
    FrontierMath v2 (Tiers 1-3): Claude Opus 4.5 scored 20.690%; Kimi K2 scored 21.404%. Kimi K2 wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricClaude Opus 4.5Kimi K2Comparison
Input / output priceUSD per 1M tokensClaude Opus 4.5$5 input / $25 outputKimi K2$0.6 input / $2.5 outputKimi K2 has the lower combined listed price.
Generation speedtokens per secondClaude Opus 4.546 tok/sKimi K243 tok/sClaude Opus 4.5 has the higher measured throughput.
First-answer latencyseconds to first tokenClaude Opus 4.51.01 sKimi K21.51 sClaude Opus 4.5 reaches the first token sooner.
Context windowmaximum listed tokensClaude Opus 4.5200KKimi K2128KClaude Opus 4.5 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkClaude Opus 4.5Kimi K2Result
Terminal-Bench 2.0Source 59.3%—Not comparable
OSWorld-VerifiedSource 66.3%—Not comparable
OSWorldSource 66.3%—Not comparable
Claw-EvalSource 59.6%—Not comparable
QwenClawBenchSource 52.3%—Not comparable
τ³-bench resultsSource 70.2%—Not comparable
VITA-BenchSource 23.3%—Not comparable
DeepPlanningSource 26.4%—Not comparable
ToolathlonSource 43.5%—Not comparable
MCP AtlasSource 42.3%—Not comparable
MCP-TasksSource 71.8%—Not comparable
WideResearchSource 76.4%—Not comparable
CyberGymSource 50.6%—Not comparable
τ²-bench resultsSource 86.3%61.1%Claude Opus 4.5 leads
Gert LabsSource 64.23%—Not comparable
JobBenchSource 32.3%—Not comparable
Coding
BenchmarkClaude Opus 4.5Kimi K2Result
SWE-bench VerifiedSource 80.9%—Not comparable
LiveCodeBench v6Source 84.8%—Not comparable
SWE-bench ProSource 57.1%—Not comparable
SWE MultilingualSource 77.5%—Not comparable
NL2RepoSource 43.2%—Not comparable
AA-SciCodeSource 47.0%34.5%Claude Opus 4.5 leads
Reasoning
BenchmarkClaude Opus 4.5Kimi K2Result
LongBench v2Source 64.4%—Not comparable
AI-NeedleSource 74%—Not comparable
AA-LCRSource 65.3%51.0%Claude Opus 4.5 leads
CritPtSource 0.3%0.0%Claude Opus 4.5 leads
Knowledge
BenchmarkClaude Opus 4.5Kimi K2Result
GPQASource 87%—Not comparable
SuperGPQASource 70.6%—Not comparable
MMLU-ProSource 89.5%—Not comparable
MMLU-ReduxSource 96.6%—Not comparable
C-EvalSource 92.2%—Not comparable
HLESource 30.8%—Not comparable
Artificial Analysis Intelligence IndexSource 34.7%19.4%Claude Opus 4.5 leads
AA-GPQA DiamondSource 81.0%76.6%Claude Opus 4.5 leads
AA-HLESource 12.9%7.0%Claude Opus 4.5 leads
AA-Omniscience IndexSource -3.9%-27.5%Claude Opus 4.5 leads
AA-Omniscience AccuracySource 40.7%26.8%Claude Opus 4.5 leads
AA-Omniscience Hallucination RateSource 75.4%74.2%Kimi K2 leads
AA MMLU-ProSource 88.9%—Not comparable
MathClaude Opus 4.5 wins
BenchmarkClaude Opus 4.5Kimi K2Result
AIME26Source 95.1%—Not comparable
HMMT Feb 2025Source 92.9%—Not comparable
HMMT Nov 2025Source 93.3%—Not comparable
HMMT Feb 2026Source 85.3%—Not comparable
MMAnswerBenchSource 84.0%—Not comparable
FrontierMath v2 (Tiers 1-3)Source 20.690%21.404%Kimi K2 leads
FrontierMath v2 (Tier 4)Source 4.167%0.000%Claude Opus 4.5 leads
Multilingual
BenchmarkClaude Opus 4.5Kimi K2Result
MMLU-ProXSource 85.7%—Not comparable
NOVA-63Source 56.7%—Not comparable
Multimodal
BenchmarkClaude Opus 4.5Kimi K2Result
MMMU-ProSource 70.6%—Not comparable
MathVisionSource 74.3%—Not comparable
CharXivSource 68.5%—Not comparable
VideoMMMUSource 84.4%—Not comparable
ScreenSpot ProSource 45.7%—Not comparable
V*Source 67.0%—Not comparable
AA-MMMU-ProSource 71.2%—Not comparable
Design Arena WebsiteSource 12771080Claude Opus 4.5 leads
Inst. Following
BenchmarkClaude Opus 4.5Kimi K2Result
IFEvalSource 90.9%—Not comparable
IFBenchSource 58%—Not comparable
AA-IFBenchSource 43.0%41.5%Claude Opus 4.5 leads
Frequently Asked Questions (2)

Which is better, Claude Opus 4.5 or Kimi K2?

Claude Opus 4.5 is ahead on BenchLM's BenchAlign leaderboard, 64.22 to 27.19. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 4.167% and 0.000%.

Which is better for math, Claude Opus 4.5 or Kimi K2?

Claude Opus 4.5 has the edge for math in this comparison, averaging 57.5 versus 16.1. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.

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