Model comparison
Claude Opus 4.5 vs Kimi K2.5 (Reasoning)
Head-to-head evidence from 19 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Opus 4.5 #34 (Supported); Kimi K2.5 (Reasoning) #57 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Opus 4.5 and Kimi K2.5 (Reasoning) share 19 comparable benchmark results. 4 of 8 categories are comparable. 40 results are unique to Claude Opus 4.5; 8 to Kimi K2.5 (Reasoning).
Updated July 20, 2026- Shared results
- 19
- Claude Opus 4.5 only
- 40
- Kimi K2.5 (Reasoning) only
- 8
- Comparable categories
- 4 / 8
Pick Claude Opus 4.5 if you want the stronger benchmark profile. Kimi K2.5 (Reasoning) only becomes the better choice if knowledge is the priority or you want the cheaper token bill.
Confidence note. This is a partial-evidence comparison with 19 shared benchmark results across 6 evidence categories; 4 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 59.35. 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 agentic, where it averages 62.6 against 55. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 59.3% to 50.8%. Kimi K2.5 (Reasoning) does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.
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 / $3.00 output per 1M tokens for Kimi K2.5 (Reasoning). That is roughly 8.3x on output cost alone. Kimi K2.5 (Reasoning) is the reasoning model in the pair, while Claude Opus 4.5 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 4.5 gives you the larger context window at 200K, compared with 128K for Kimi K2.5 (Reasoning).
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 | Claude Opus 4.5 | Δ | Kimi K2.5 (Reasoning) |
|---|---|---|---|
| Knowledge | Claude Opus 4.558.1 | Margin→ 29.1 | Kimi K2.5 (Reasoning)87.2 |
| Multimodal | Claude Opus 4.569.9 | Margin→ 8.6 | Kimi K2.5 (Reasoning)78.5 |
| Agentic | Claude Opus 4.562.6 | Margin← 7.6 | Kimi K2.5 (Reasoning)55.0 |
| Coding | Claude Opus 4.571.7 | Margin→ 5.1 | Kimi K2.5 (Reasoning)76.8 |
| Reasoning | Claude Opus 4.564.4 | MarginNo overlap | Kimi K2.5 (Reasoning)Not measured |
| Math | Claude Opus 4.557.5 | MarginNo overlap | Kimi K2.5 (Reasoning)Not measured |
| Multilingual | Claude Opus 4.585.7 | MarginNo overlap | Kimi K2.5 (Reasoning)Not measured |
| Inst. Following | Claude Opus 4.569.5 | MarginNo overlap | Kimi K2.5 (Reasoning)Not measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
Terminal-Bench 2.0
AgenticA 59.3%B 50.8%Winner: Claude Opus 4.5Δ 8.5Terminal-Bench 2.0: Claude Opus 4.5 scored 59.3%; Kimi K2.5 (Reasoning) scored 50.8%. Claude Opus 4.5 wins this benchmark. - Source ↗
MMMU-Pro
MultimodalA 70.6%B 78.5%Winner: Kimi K2.5 (Reasoning)Δ 7.9MMMU-Pro: Claude Opus 4.5 scored 70.6%; Kimi K2.5 (Reasoning) scored 78.5%. Kimi K2.5 (Reasoning) wins this benchmark. - Source ↗
SWE-bench Verified
CodingA 80.9%B 76.8%Winner: Claude Opus 4.5Δ 4.1SWE-bench Verified: Claude Opus 4.5 scored 80.9%; Kimi K2.5 (Reasoning) scored 76.8%. Claude Opus 4.5 wins this benchmark. - Source ↗
MMLU-Pro
KnowledgeA 89.5%B 87.1%Winner: Claude Opus 4.5Δ 2.4MMLU-Pro: Claude Opus 4.5 scored 89.5%; Kimi K2.5 (Reasoning) scored 87.1%. Claude Opus 4.5 wins this benchmark. - Source ↗
GPQA
KnowledgeA 87%B 87.6%Winner: Kimi K2.5 (Reasoning)Δ 0.6GPQA: Claude Opus 4.5 scored 87%; Kimi K2.5 (Reasoning) scored 87.6%. Kimi K2.5 (Reasoning) wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Opus 4.5 | Kimi K2.5 (Reasoning) | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Opus 4.5$5 input / $25 output | Kimi K2.5 (Reasoning)$0.6 input / $3 output | Kimi K2.5 (Reasoning) has the lower combined listed price. |
| Generation speedtokens per second | Claude Opus 4.546 tok/s | Kimi K2.5 (Reasoning)Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Opus 4.51.01 s | Kimi K2.5 (Reasoning)Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Opus 4.5200K | Kimi K2.5 (Reasoning)128K | Claude Opus 4.5 lists the larger context window. |
Benchmark Deep Dive
AgenticClaude Opus 4.5 wins21 benchmarks
| Benchmark | Claude Opus 4.5 | Kimi K2.5 (Reasoning) | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 59.3% | 50.8% | Claude Opus 4.5 leads |
| 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% | 95.9% | Kimi K2.5 (Reasoning) leads |
| Gert LabsSource | 64.23% | 32.58% | Claude Opus 4.5 leads |
| JobBenchSource | 32.3% | — | Not comparable |
| BrowseCompSource | — | 60.6% | Not comparable |
| APEX-Agents-AASource | — | 11.5% | Not comparable |
| AA Agentic IndexSource | — | 21.7% | Not comparable |
| GDPval-AASource | — | 25.4% | Not comparable |
| GDPval-AASource | — | 1009 | Not comparable |
CodingKimi K2.5 (Reasoning) wins8 benchmarks
| Benchmark | Claude Opus 4.5 | Kimi K2.5 (Reasoning) | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 80.9% | 76.8% | Claude Opus 4.5 leads |
| 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% | 49.0% | Kimi K2.5 (Reasoning) leads |
| Vibe Code BenchSource | — | 17.54% | Not comparable |
| AA Coding IndexSource | — | 46.8% | Not comparable |
Reasoning4 benchmarks
KnowledgeKimi K2.5 (Reasoning) wins13 benchmarks
| Benchmark | Claude Opus 4.5 | Kimi K2.5 (Reasoning) | Result |
|---|---|---|---|
| GPQASource | 87% | 87.6% | Kimi K2.5 (Reasoning) leads |
| SuperGPQASource | 70.6% | — | Not comparable |
| MMLU-ProSource | 89.5% | 87.1% | Claude Opus 4.5 leads |
| MMLU-ReduxSource | 96.6% | — | Not comparable |
| C-EvalSource | 92.2% | — | Not comparable |
| HLESource | 30.8% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 34.7% | 35.4% | Kimi K2.5 (Reasoning) leads |
| AA-GPQA DiamondSource | 81.0% | 87.9% | Kimi K2.5 (Reasoning) leads |
| AA-HLESource | 12.9% | 29.4% | Kimi K2.5 (Reasoning) leads |
| AA-Omniscience IndexSource | -3.9% | -8.1% | Claude Opus 4.5 leads |
| AA-Omniscience AccuracySource | 40.7% | 34.3% | Claude Opus 4.5 leads |
| AA-Omniscience Hallucination RateSource | 75.4% | 64.6% | Kimi K2.5 (Reasoning) leads |
| AA MMLU-ProSource | 88.9% | — | Not comparable |
Math8 benchmarks
| Benchmark | Claude Opus 4.5 | Kimi K2.5 (Reasoning) | Result |
|---|---|---|---|
| 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% | — | Not comparable |
| FrontierMath v2 (Tier 4)Source | 4.167% | — | Not comparable |
| AIME 2025Source | — | 96.1% | Not comparable |
Multilingual2 benchmarks
MultimodalKimi K2.5 (Reasoning) wins8 benchmarks
| Benchmark | Claude Opus 4.5 | Kimi K2.5 (Reasoning) | Result |
|---|---|---|---|
| MMMU-ProSource | 70.6% | 78.5% | Kimi K2.5 (Reasoning) leads |
| 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% | 75.4% | Kimi K2.5 (Reasoning) leads |
| Design Arena WebsiteSource | 1279 | 1282 | Kimi K2.5 (Reasoning) leads |
Frequently Asked Questions (5)
Which is better, Claude Opus 4.5 or Kimi K2.5 (Reasoning)?
Claude Opus 4.5 is ahead on BenchLM's BenchAlign leaderboard, 64.22 to 59.35. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 59.3% and 50.8%.
Which is better for knowledge tasks, Claude Opus 4.5 or Kimi K2.5 (Reasoning)?
Kimi K2.5 (Reasoning) has the edge for knowledge tasks in this comparison, averaging 87.2 versus 58.1. Inside this category, AA-HLE is the benchmark that creates the most daylight between them.
Which is better for coding, Claude Opus 4.5 or Kimi K2.5 (Reasoning)?
Kimi K2.5 (Reasoning) has the edge for coding in this comparison, averaging 76.8 versus 71.7. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
Which is better for agentic tasks, Claude Opus 4.5 or Kimi K2.5 (Reasoning)?
Claude Opus 4.5 has the edge for agentic tasks in this comparison, averaging 62.6 versus 55. Inside this category, Gert Labs is the benchmark that creates the most daylight between them.
Which is better for multimodal and grounded tasks, Claude Opus 4.5 or Kimi K2.5 (Reasoning)?
Kimi K2.5 (Reasoning) has the edge for multimodal and grounded tasks in this comparison, averaging 78.5 versus 69.9. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.
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