Model comparison
Claude 3.5 Sonnet vs Kimi K2
Head-to-head evidence from 2 shared benchmark results across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude 3.5 Sonnet #132 (Estimated); Kimi K2 #189 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude 3.5 Sonnet and Kimi K2 share 2 comparable benchmark results. 1 of 8 categories are comparable. 2 results are unique to Claude 3.5 Sonnet; 12 to Kimi K2.
Updated July 20, 2026- Shared results
- 2
- Claude 3.5 Sonnet only
- 2
- Kimi K2 only
- 12
- Comparable categories
- 1 / 8
Pick Claude 3.5 Sonnet if you want the stronger benchmark profile. Kimi K2 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 2 shared benchmark results across 1 evidence category; 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 3.5 Sonnet is clearly ahead on the BenchAlign aggregate, 47.74 to 27.19. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude 3.5 Sonnet is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $0.60 input / $2.50 output per 1M tokens for Kimi K2. That is roughly 6.0x on output cost alone. Claude 3.5 Sonnet 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 | Claude 3.5 Sonnet | Δ | Kimi K2 |
|---|---|---|---|
| Math | Claude 3.5 Sonnet1.6 | Margin→ 14.5 | Kimi K216.1 |
| Coding | Claude 3.5 Sonnet49.0 | MarginNo overlap | Kimi K2Not measured |
| Knowledge | Claude 3.5 Sonnet59.4 | MarginNo overlap | Kimi K2Not measured |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
FrontierMath v2 (Tiers 1-3)
MathA 2.069%B 21.404%Winner: Kimi K2Δ 19.3FrontierMath v2 (Tiers 1-3): Claude 3.5 Sonnet scored 2.069%; 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.
| Metric | Claude 3.5 Sonnet | Kimi K2 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude 3.5 Sonnet$3 input / $15 output | Kimi K2$0.6 input / $2.5 output | Kimi K2 has the lower combined listed price. |
| Generation speedtokens per second | Claude 3.5 SonnetNot available | Kimi K243 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude 3.5 SonnetNot available | Kimi K21.51 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude 3.5 Sonnet200K | Kimi K2128K | Claude 3.5 Sonnet lists the larger context window. |
Benchmark Deep Dive
Agentic1 benchmarks
| Benchmark | Claude 3.5 Sonnet | Kimi K2 | Result |
|---|---|---|---|
| τ²-bench resultsSource | — | 61.1% | Not comparable |
Coding2 benchmarks
Reasoning2 benchmarks
Knowledge7 benchmarks
| Benchmark | Claude 3.5 Sonnet | Kimi K2 | Result |
|---|---|---|---|
| GPQASource | 59.4% | — | Not comparable |
| Artificial Analysis Intelligence IndexSource | — | 19.4% | Not comparable |
| AA-GPQA DiamondSource | — | 76.6% | Not comparable |
| AA-HLESource | — | 7.0% | Not comparable |
| AA-Omniscience IndexSource | — | -27.5% | Not comparable |
| AA-Omniscience AccuracySource | — | 26.8% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 74.2% | Not comparable |
MathKimi K2 wins2 benchmarks
Multimodal1 benchmarks
| Benchmark | Claude 3.5 Sonnet | Kimi K2 | Result |
|---|---|---|---|
| Design Arena WebsiteSource | — | 1083 | Not comparable |
Inst. Following1 benchmarks
| Benchmark | Claude 3.5 Sonnet | Kimi K2 | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 41.5% | Not comparable |
Frequently Asked Questions (2)
Which is better, Claude 3.5 Sonnet or Kimi K2?
Claude 3.5 Sonnet is ahead on BenchLM's BenchAlign leaderboard, 47.74 to 27.19. The biggest single separator in this matchup is FrontierMath v2 (Tiers 1-3), where the scores are 2.069% and 21.404%.
Which is better for math, Claude 3.5 Sonnet or Kimi K2?
Kimi K2 has the edge for math in this comparison, averaging 16.1 versus 1.6. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.
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