Model comparison
Claude Sonnet 4.6 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 Sonnet 4.6 #32 (Supported); Kimi K2.5 (Reasoning) #57 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Sonnet 4.6 and Kimi K2.5 (Reasoning) share 19 comparable benchmark results. 4 of 8 categories are comparable. 14 results are unique to Claude Sonnet 4.6; 8 to Kimi K2.5 (Reasoning).
Updated July 20, 2026- Shared results
- 19
- Claude Sonnet 4.6 only
- 14
- Kimi K2.5 (Reasoning) only
- 8
- Comparable categories
- 4 / 8
Pick Claude Sonnet 4.6 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 Sonnet 4.6 is clearly ahead on the BenchAlign aggregate, 65.07 to 59.35. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Sonnet 4.6's sharpest advantage is in agentic, where it averages 65.2 against 55. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 59.1% 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 Sonnet 4.6 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $0.60 input / $3.00 output per 1M tokens for Kimi K2.5 (Reasoning). That is roughly 5.0x on output cost alone. Kimi K2.5 (Reasoning) is the reasoning model in the pair, while Claude Sonnet 4.6 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 Sonnet 4.6 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 Sonnet 4.6 | Δ | Kimi K2.5 (Reasoning) |
|---|---|---|---|
| Knowledge | Claude Sonnet 4.666.0 | Margin→ 21.2 | Kimi K2.5 (Reasoning)87.2 |
| Agentic | Claude Sonnet 4.665.2 | Margin← 10.2 | Kimi K2.5 (Reasoning)55.0 |
| Coding | Claude Sonnet 4.669.1 | Margin→ 7.7 | Kimi K2.5 (Reasoning)76.8 |
| Multimodal | Claude Sonnet 4.677.4 | Margin→ 1.1 | Kimi K2.5 (Reasoning)78.5 |
| Math | Claude Sonnet 4.626.4 | 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 59.1%B 50.8%Winner: Claude Sonnet 4.6Δ 8.3Terminal-Bench 2.0: Claude Sonnet 4.6 scored 59.1%; Kimi K2.5 (Reasoning) scored 50.8%. Claude Sonnet 4.6 wins this benchmark. - Source ↗
MMLU-Pro
KnowledgeA 79.2%B 87.1%Winner: Kimi K2.5 (Reasoning)Δ 7.9MMLU-Pro: Claude Sonnet 4.6 scored 79.2%; Kimi K2.5 (Reasoning) scored 87.1%. Kimi K2.5 (Reasoning) wins this benchmark. - Source ↗
SWE-bench Verified
CodingA 79.6%B 76.8%Winner: Claude Sonnet 4.6Δ 2.8SWE-bench Verified: Claude Sonnet 4.6 scored 79.6%; Kimi K2.5 (Reasoning) scored 76.8%. Claude Sonnet 4.6 wins this benchmark. - Source ↗
GPQA
KnowledgeA 89.9%B 87.6%Winner: Claude Sonnet 4.6Δ 2.3GPQA: Claude Sonnet 4.6 scored 89.9%; Kimi K2.5 (Reasoning) scored 87.6%. Claude Sonnet 4.6 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Sonnet 4.6 | Kimi K2.5 (Reasoning) | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Sonnet 4.6$3 input / $15 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 Sonnet 4.644 tok/s | Kimi K2.5 (Reasoning)Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Sonnet 4.61.48 s | Kimi K2.5 (Reasoning)Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Sonnet 4.6200K | Kimi K2.5 (Reasoning)128K | Claude Sonnet 4.6 lists the larger context window. |
Benchmark Deep Dive
AgenticClaude Sonnet 4.6 wins13 benchmarks
| Benchmark | Claude Sonnet 4.6 | Kimi K2.5 (Reasoning) | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 59.1% | 50.8% | Claude Sonnet 4.6 leads |
| OSWorld-VerifiedSource | 72.1% | — | Not comparable |
| Claw-EvalSource | 67.8% | — | Not comparable |
| CyberGymSource | 65.2% | — | Not comparable |
| τ²-bench resultsSource | 79.5% | 95.9% | Kimi K2.5 (Reasoning) leads |
| Gert LabsSource | 62.92% | 32.58% | Claude Sonnet 4.6 leads |
| OSWorld 2.0Source | 8.3% | — | Not comparable |
| JobBenchSource | 36.9% | — | 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 Sonnet 4.6 | Kimi K2.5 (Reasoning) | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 79.6% | 76.8% | Claude Sonnet 4.6 leads |
| SWE-RebenchSource | 60.7% | — | Not comparable |
| React Native EvalsSource | 80.6% | — | Not comparable |
| Vibe Code BenchSource | 51.48% | 17.54% | Claude Sonnet 4.6 leads |
| cursorBench31Source | 48.8% | — | Not comparable |
| AA-SciCodeSource | 46.9% | 49.0% | Kimi K2.5 (Reasoning) leads |
| FrontierCode 1.1 MainSource | 24.3% | — | Not comparable |
| AA Coding IndexSource | — | 46.8% | Not comparable |
Reasoning2 benchmarks
KnowledgeKimi K2.5 (Reasoning) wins10 benchmarks
| Benchmark | Claude Sonnet 4.6 | Kimi K2.5 (Reasoning) | Result |
|---|---|---|---|
| GPQASource | 89.9% | 87.6% | Claude Sonnet 4.6 leads |
| SuperGPQASource | 95% | — | Not comparable |
| MMLU-ProSource | 79.2% | 87.1% | Kimi K2.5 (Reasoning) leads |
| HLESource | 49% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | 35.9% | 35.4% | Claude Sonnet 4.6 leads |
| AA-GPQA DiamondSource | 79.9% | 87.9% | Kimi K2.5 (Reasoning) leads |
| AA-HLESource | 13.2% | 29.4% | Kimi K2.5 (Reasoning) leads |
| AA-Omniscience IndexSource | -2.9% | -8.1% | Claude Sonnet 4.6 leads |
| AA-Omniscience AccuracySource | 38.0% | 34.3% | Claude Sonnet 4.6 leads |
| AA-Omniscience Hallucination RateSource | 65.9% | 64.6% | Kimi K2.5 (Reasoning) leads |
Math3 benchmarks
MultimodalKimi K2.5 (Reasoning) wins4 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude Sonnet 4.6 | Kimi K2.5 (Reasoning) | Result |
|---|---|---|---|
| AA-IFBenchSource | 41.2% | 70.2% | Kimi K2.5 (Reasoning) leads |
Frequently Asked Questions (5)
Which is better, Claude Sonnet 4.6 or Kimi K2.5 (Reasoning)?
Claude Sonnet 4.6 is ahead on BenchLM's BenchAlign leaderboard, 65.07 to 59.35. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 59.1% and 50.8%.
Which is better for knowledge tasks, Claude Sonnet 4.6 or Kimi K2.5 (Reasoning)?
Kimi K2.5 (Reasoning) has the edge for knowledge tasks in this comparison, averaging 87.2 versus 66. Inside this category, AA-HLE is the benchmark that creates the most daylight between them.
Which is better for coding, Claude Sonnet 4.6 or Kimi K2.5 (Reasoning)?
Kimi K2.5 (Reasoning) has the edge for coding in this comparison, averaging 76.8 versus 69.1. Inside this category, Vibe Code Bench is the benchmark that creates the most daylight between them.
Which is better for agentic tasks, Claude Sonnet 4.6 or Kimi K2.5 (Reasoning)?
Claude Sonnet 4.6 has the edge for agentic tasks in this comparison, averaging 65.2 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 Sonnet 4.6 or Kimi K2.5 (Reasoning)?
Kimi K2.5 (Reasoning) has the edge for multimodal and grounded tasks in this comparison, averaging 78.5 versus 77.4. Inside this category, Design Arena Website is the benchmark that creates the most daylight between them.
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