Claude Sonnet 5.5 vs Kimi K3
Claude Sonnet 5.5 (Anthropic) and Kimi K3 (Moonshot) compared on benchmarks, pricing, context window, and use-case rankings.
- Kimi K3 is cheaper on input tokens — $1.99 vs $2.00 per 1M.
- Kimi K3 has a larger context window (1M vs 1M tokens).
- Claude Sonnet 5.5 ranks higher for coding (96th vs 94th percentile).
| Attribute | Claude Sonnet 5.5 | Kimi K3 |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | — | 158 |
| Coding | 96 | 94 |
| Math | 91 | 74 |
| Reasoning & Knowledge | 76 | 70 |
| Agentic & Tools | 100 | 67 |
| Specifications | ||
| Developer | Anthropic | Moonshot |
| Family | Claude | Kimi |
| Released | Sep 28, 2026 | Jul 16, 2026 |
| Parameters | — | 2.8T |
| Availability | API access | Open weights (non-commercial) |
| Context window | 1M | 1M |
| Price — $/M input | $2.00 | $1.99 |
| Price — $/M output | $10.00 | $9.00 |
| Inputs | text, image, file | text, image, video |
| Outputs | text | text |
| Benchmarks | ||
| AIME 2024/2025 | 100% | 97% |
| APEX | 76% | 51% |
| GPQA Diamond | 96% | 93% |
| SimpleQA Verified | 47% | 51% |
| WebDev Arena | 1699 | 1674 |
| ARC-AGI | — | 95% |
| ARC-AGI-2 | — | 60% |
| Humanity's Last Exam | — | 47% |
| SciCode | — | 60% |
| SimpleBench | — | 61% |
| WeirdML | — | 83% |
Use-case scores are 0–100 percentile composites across each area’s benchmarks, ranked against every model from the past year. Highlighted cells lead each row. Open a model for the full picture.
Frequently asked questions
Which is cheaper, Claude Sonnet 5.5 or Kimi K3?
Kimi K3 is cheaper on input tokens at $1.99 per million, versus $2.00 (representative OpenRouter pricing).
Which has a larger context window, Claude Sonnet 5.5 or Kimi K3?
Kimi K3 supports up to 1M tokens, compared with 1M for the other.
Which is better for coding, Claude Sonnet 5.5 or Kimi K3?
Across coding benchmarks like SWE-bench Verified and Terminal-Bench, Claude Sonnet 5.5 ranks higher — 96th vs 94th percentile among the models tracked on Model Beat.
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Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.