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Model comparison

Claude Opus 4.8 vs Kimi K2.5

Data verified

Head-to-head evidence from 31 shared benchmark results across 7 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

78.34/100
Margin
18.7pts
← winning
Kimi K2.5
Moonshot AI
59.66/100
3 category wins2 category wins

Public leaderboard positions: Claude Opus 4.8 #5 (Supported); Kimi K2.5 #54 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Opus 4.8 and Kimi K2.5 share 31 comparable benchmark results. 5 of 8 categories are comparable. 22 results are unique to Claude Opus 4.8; 32 to Kimi K2.5.

Updated July 23, 2026
Shared results
31
Claude Opus 4.8 only
22
Kimi K2.5 only
32
Comparable categories
5 / 8

Pick Claude Opus 4.8 if you want the stronger benchmark profile. Kimi K2.5 only becomes the better choice if mathematics is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 31 shared benchmark results across 7 evidence categories; 5 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 4.8 is clearly ahead on the BenchAlign aggregate, 78.34 to 59.66. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Claude Opus 4.8's sharpest advantage is in agentic, where it averages 80.3 against 55. The single biggest benchmark swing on the page is HLE, 57.9% to 30.1%. Kimi K2.5 does hit back in mathematics, so the answer changes if that is the part of the workload you care about most.

Claude Opus 4.8 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $0.60 input / $3.00 output per 1M tokens for Kimi K2.5. That is roughly 8.3x on output cost alone. Claude Opus 4.8 is the reasoning model in the pair, while Kimi K2.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Claude Opus 4.8 gives you the larger context window at 1M, compared with 256K for Kimi K2.5.

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 4.8 and Kimi K2.5
CategoryClaude Opus 4.8ΔKimi K2.5
AgenticClaude Opus 4.880.3Margin← 25.3Kimi K2.555.0
CodingClaude Opus 4.881.1Margin← 21.7Kimi K2.559.4
MathClaude Opus 4.853.9Margin→ 6.7Kimi K2.560.6
KnowledgeClaude Opus 4.862.7Margin← 5.8Kimi K2.556.9
MultimodalClaude Opus 4.877.0Margin→ 1.5Kimi K2.578.5
ReasoningClaude Opus 4.8Not measuredMarginNo overlapKimi K2.561.0
MultilingualClaude Opus 4.8Not measuredMarginNo overlapKimi K2.582.3
Inst. FollowingClaude Opus 4.8Not measuredMarginNo overlapKimi K2.593.9

Decisive benchmark drivers

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

More
A · Claude Opus 4.8B · Kimi K2.5

  1. HLE

    Knowledge
    Source ↗
    A 57.9%B 30.1%
    Winner: Claude Opus 4.8Δ 27.8
    HLE: Claude Opus 4.8 scored 57.9%; Kimi K2.5 scored 30.1%. Claude Opus 4.8 wins this benchmark.

  2. FrontierMath v2 (Tier 4)

    Math
    Source ↗
    A 31.250%B 4.200%
    Winner: Claude Opus 4.8Δ 27.1
    FrontierMath v2 (Tier 4): Claude Opus 4.8 scored 31.250%; Kimi K2.5 scored 4.200%. Claude Opus 4.8 wins this benchmark.

  3. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 74.6%B 50.8%
    Winner: Claude Opus 4.8Δ 23.8
    Terminal-Bench 2.0: Claude Opus 4.8 scored 74.6%; Kimi K2.5 scored 50.8%. Claude Opus 4.8 wins this benchmark.

  4. BrowseComp

    Agentic
    Source ↗
    A 84.3%B 60.6%
    Winner: Claude Opus 4.8Δ 23.7
    BrowseComp: Claude Opus 4.8 scored 84.3%; Kimi K2.5 scored 60.6%. Claude Opus 4.8 wins this benchmark.

  5. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 47.241%B 27.900%
    Winner: Claude Opus 4.8Δ 19.3
    FrontierMath v2 (Tiers 1-3): Claude Opus 4.8 scored 47.241%; Kimi K2.5 scored 27.900%. Claude Opus 4.8 wins this benchmark.

Operational comparison

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

MetricClaude Opus 4.8Kimi K2.5Comparison
Input / output priceUSD per 1M tokensClaude Opus 4.8$5 input / $25 outputKimi K2.5$0.6 input / $3 outputKimi K2.5 has the lower combined listed price.
Generation speedtokens per secondClaude Opus 4.8Not availableKimi K2.545 tok/sA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Opus 4.8Not availableKimi K2.52.38 sA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Opus 4.81MKimi K2.5256KClaude Opus 4.8 lists the larger context window.

Benchmark Deep Dive

AgenticClaude Opus 4.8 wins
BenchmarkClaude Opus 4.8Kimi K2.5Result
Terminal-Bench 2.0Source 74.6%50.8%Claude Opus 4.8 leads
BrowseCompSource 84.3%60.6%Claude Opus 4.8 leads
DeepSearchQASource 93.1%77.1%Claude Opus 4.8 leads
OSWorld-VerifiedSource 83.4%—Not comparable
Finance Agent v2Source 53.9%—Not comparable
GDPval-AASource 15941009Claude Opus 4.8 leads
MCP AtlasSource 82.2%29.5%Claude Opus 4.8 leads
ToolathlonSource 59.9%27.8%Claude Opus 4.8 leads
Gert LabsSource 72.97%45.88%Claude Opus 4.8 leads
AA Agentic IndexSource 47.2%21.7%Claude Opus 4.8 leads
τ²-bench resultsSource 94.4%95.9%Kimi K2.5 leads
GDPval-AASource 54.7%25.4%Claude Opus 4.8 leads
ResearchClawBenchSource 21.1%14.0%Claude Opus 4.8 leads
OSWorld 2.0Source 20.6%—Not comparable
AA BriefcaseSource 1347—Not comparable
AA AutomationBenchSource 48.5%—Not comparable
AA EnterpriseOps-GymSource 44.0%—Not comparable
AA Harvey LABSource 91.1%—Not comparable
AA Tau3 BankingSource 27.6%—Not comparable
terminalBenchHardSource 58.3%—Not comparable
aaTerminalBench21Source 84.6%—Not comparable
Claw-EvalSource —52.3%Not comparable
QwenClawBenchSource —54.3%Not comparable
τ³-bench resultsSource —65.7%Not comparable
DeepPlanningSource —14.4%Not comparable
MCP-TasksSource —59.1%Not comparable
WideResearchSource —72.7%Not comparable
APEX-Agents-AASource —11.5%Not comparable
JobBenchSource —8.7%Not comparable
CodingClaude Opus 4.8 wins
BenchmarkClaude Opus 4.8Kimi K2.5Result
SWE-bench VerifiedSource 88.6%76.8%Claude Opus 4.8 leads
SWE-bench ProSource 69.2%50.7%Claude Opus 4.8 leads
SWE MultilingualSource 84.4%73%Claude Opus 4.8 leads
SWE MultimodalSource 38.4%—Not comparable
Terminal-Bench 2.0Source 74.6%—Not comparable
cursorBench31Source 58.4%—Not comparable
cursorBench32Source 62.3%—Not comparable
AA Coding IndexSource 74.3%46.8%Claude Opus 4.8 leads
AA-SciCodeSource 53.5%49.0%Claude Opus 4.8 leads
FrontierCode 1.1 MainSource 46.5%—Not comparable
SWE-bench Verified*Source —70.8%Not comparable
LiveCodeBench v6Source —85.0%Not comparable
SWE-RebenchSource —58.5%Not comparable
React Native EvalsSource —77.2%Not comparable
SciCodeSource —48.7%Not comparable
Reasoning
BenchmarkClaude Opus 4.8Kimi K2.5Result
AA-LCRSource 67.7%65.3%Claude Opus 4.8 leads
CritPtSource 20.9%3.1%Claude Opus 4.8 leads
LongBench v2Source —61%Not comparable
KnowledgeClaude Opus 4.8 wins
BenchmarkClaude Opus 4.8Kimi K2.5Result
GPQASource 93.6%87.6%Claude Opus 4.8 leads
GPQA-DSource 93.6%87.6%Claude Opus 4.8 leads
HLESource 57.9%30.1%Claude Opus 4.8 leads
HLE w/o toolsSource 49.8%—Not comparable
Artificial Analysis Intelligence IndexSource 55.7%35.4%Claude Opus 4.8 leads
AA-GPQA DiamondSource 92.0%87.9%Claude Opus 4.8 leads
AA-HLESource 45.7%29.4%Claude Opus 4.8 leads
AA-Omniscience IndexSource 27.4%-8.1%Claude Opus 4.8 leads
AA-Omniscience AccuracySource 46.6%34.3%Claude Opus 4.8 leads
AA-Omniscience Hallucination RateSource 35.9%64.6%Claude Opus 4.8 leads
SuperGPQASource —69.2%Not comparable
MMLU-ProSource —87.1%Not comparable
MMLU-Pro (Arcee)Source —87.1%Not comparable
MathKimi K2.5 wins
BenchmarkClaude Opus 4.8Kimi K2.5Result
USAMO 2026Source 96.7%—Not comparable
FrontierMath v2 (Tiers 1-3)Source 47.241%27.900%Claude Opus 4.8 leads
FrontierMath v2 (Tier 4)Source 31.250%4.200%Claude Opus 4.8 leads
AIME 2025Source —96.1%Not comparable
AIME26Source —95.8%Not comparable
AIME25 (Arcee)Source —96.3%Not comparable
HMMT Feb 2025Source —95.4%Not comparable
HMMT Nov 2025Source —91.1%Not comparable
HMMT Feb 2026Source —87.1%Not comparable
MMAnswerBenchSource —81.8%Not comparable
Multilingual
BenchmarkClaude Opus 4.8Kimi K2.5Result
INCLUDESource 87.6%—Not comparable
MMLU-ProXSource —82.3%Not comparable
NOVA-63Source —56.0%Not comparable
MultimodalKimi K2.5 wins
BenchmarkClaude Opus 4.8Kimi K2.5Result
OfficeQA ProSource 66.2%—Not comparable
ScreenSpot ProSource 87.9%—Not comparable
CharXivSource 89.9%—Not comparable
CharXiv w/o toolsSource 80.5%—Not comparable
Design Arena WebsiteSource 12701279Kimi K2.5 leads
MMMU-ProSource —78.5%Not comparable
Video-MMESource —87.4%Not comparable
MMVUSource —80.4%Not comparable
VideoMMMUSource —86.6%Not comparable
AA-MMMU-ProSource —75.4%Not comparable
Inst. Following
BenchmarkClaude Opus 4.8Kimi K2.5Result
AA-IFBenchSource 62.2%70.2%Kimi K2.5 leads
IFEvalSource —93.9%Not comparable
Frequently Asked Questions (6)

Which is better, Claude Opus 4.8 or Kimi K2.5?

Claude Opus 4.8 is ahead on BenchLM's BenchAlign leaderboard, 78.34 to 59.66. The biggest single separator in this matchup is HLE, where the scores are 57.9% and 30.1%.

Which is better for knowledge tasks, Claude Opus 4.8 or Kimi K2.5?

Claude Opus 4.8 has the edge for knowledge tasks in this comparison, averaging 62.7 versus 56.9. Inside this category, AA-Omniscience Index is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Opus 4.8 or Kimi K2.5?

Claude Opus 4.8 has the edge for coding in this comparison, averaging 81.1 versus 59.4. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.

Which is better for math, Claude Opus 4.8 or Kimi K2.5?

Kimi K2.5 has the edge for math in this comparison, averaging 60.6 versus 53.9. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Claude Opus 4.8 or Kimi K2.5?

Claude Opus 4.8 has the edge for agentic tasks in this comparison, averaging 80.3 versus 55. Inside this category, GDPval-AA is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Claude Opus 4.8 or Kimi K2.5?

Kimi K2.5 has the edge for multimodal and grounded tasks in this comparison, averaging 78.5 versus 77. Inside this category, Design Arena Website is the benchmark that creates the most daylight between them.

Self-host vs API cost

Estimates at 50,000 req/day · 1000 tokens/req average.

Claude Opus 4.8
API / mo$22,500
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
Kimi K2.5
API / mo$2,700
Self-host / mo$5,221
Break-even132M/day
Model the full break-even

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