Pairwise benchmark snapshot · Aug 1, 2026
In this head-to-head showdown, Claude Sonnet 4.5 delivers higher overall intelligence and human-preferred responses (Elo 1,524 vs 1,465), while Claude Sonnet 4.5 leads in SWE-bench software engineering benchmarks (70.1%), while Kimi K2 is more budget-friendly at $1.4/1M per 1M output tokens, while Claude Sonnet 4.5 provides faster response streaming (88 tok/s). Review the complete breakdown below to determine which model best fits your performance and budget requirements.
9 direct benchmark disciplines evaluated across capability, speed, and cost
Workhorse Anthropic model: most of Opus coding quality at a mid-tier price.
Moonshot foundation model with strong native bilingual reasoning and 65.8% SWE-bench Verified coding baseline.
Currently comparing Claude Sonnet 4.5 vs Kimi K2. Alternative family tiers available.
Δ 59 Arena Elo pts
88 tok/s
$1.4 / 1M output
Relative percentile scores computed across all active models in the benchmark catalog.
Comparing top Western standard models with China's leading frontier rival across 6 skill dimensions. Tap any spoke or dot to inspect.
Category wins across reasoning intelligence, generation speed, and token cost.
Preference Elo, Coding proficiency, SWE-bench & LiveBench accuracy
Generation throughput and time to first token responsiveness
Cost per million tokens and max context window length
| Benchmark | Claude Sonnet 4.5 | Kimi K2 | Advantage Delta |
|---|---|---|---|
| Preference Elo | +59 | ||
| Coding Elo | +61 | ||
| LiveBench | +4.6% | ||
| SWE-bench | +4.3% | ||
| GPQA Diamond | +3.7% | ||
| Time to first token | — | ||
| Output speed | 88 tok/s | 85 tok/s | +3 tok/s |
| Input price | $0.35/1M | +$2.65/1M | |
| Output price | $1.4/1M | +$13.6/1M | |
| Context window | +72k |
Simulate monthly production API costs in USD (US Dollar).
Kimi K2 is estimated to save $296.75/month ($3,561/year).
Higher SWE-bench (70.1%).
Lower output list price ($1.4/1M).
Lower TTFT (240 ms).
Larger window (200k).
Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5).
| Target Workload | Recommended Pick | Evaluation Rationale |
|---|---|---|
| Repo / coding agents | Claude Sonnet 4.5 | Higher SWE-bench (70.1%). |
| High-volume chat | Kimi K2 | Lower output list price ($1.4/1M). |
| Voice / low-latency UI | Claude Sonnet 4.5 | Lower TTFT (240 ms). |
| Long-document RAG | Claude Sonnet 4.5 | Larger window (200k). |
| Screenshots / vision | Claude Sonnet 4.5 | Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4.5). |
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Verified Head-to-Head Telemetry