Claude Opus 5.5 vs Kimi K3
Claude Opus 5.5 (Anthropic) and Kimi K3 (Moonshot) compared on benchmarks, pricing, context window, and use-case rankings.
- Kimi K3 is cheaper on input tokens — $2.10 vs $4.00 per 1M.
- Kimi K3 has a larger context window (1M vs 1M tokens).
- Claude Opus 5.5 ranks higher for coding (100th vs 97th percentile).
| Attribute | Claude Opus 5.5 | Kimi K3 |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | — | 158 |
| Coding | 100 | 97 |
| Math | — | 80 |
| Reasoning & Knowledge | 100 | 72 |
| Agentic & Tools | — | 72 |
| Specifications | ||
| Developer | Anthropic | Moonshot |
| Family | Claude | Kimi |
| Released | Sep 22, 2026 | Jul 16, 2026 |
| Parameters | — | 2.8T |
| Availability | — | Open weights (non-commercial) |
| Context window | 1M | 1M |
| Price — $/M input | $4.00 | $2.10 |
| Price — $/M output | $20.00 | $10.95 |
| Inputs | text, image, file | text, image, video |
| Outputs | text | text |
| Benchmarks | ||
| Humanity's Last Exam | 61% | 47% |
| SciCode | 67% | 60% |
| AIME 2024/2025 | — | 97% |
| APEX | — | 51% |
| ARC-AGI | — | 95% |
| ARC-AGI-2 | — | 60% |
| GPQA Diamond | — | 93% |
| SimpleBench | — | 61% |
| SimpleQA Verified | — | 51% |
| WebDev Arena | — | 1674 |
| 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 Opus 5.5 or Kimi K3?
Kimi K3 is cheaper on input tokens at $2.10 per million, versus $4.00 (representative OpenRouter pricing).
Which has a larger context window, Claude Opus 5.5 or Kimi K3?
Kimi K3 supports up to 1M tokens, compared with 1M for the other.
Which is better for coding, Claude Opus 5.5 or Kimi K3?
Across coding benchmarks like SWE-bench Verified and Terminal-Bench, Claude Opus 5.5 ranks higher — 100th vs 97th 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.