Kimi K3.1 Pro vs Claude Sonnet 5.5
Kimi K3.1 Pro is from Moonshot. Claude Sonnet 5.5 is from Anthropic. Kimi K3.1 Pro costs $10.00 per million output tokens. Claude Sonnet 5.5 costs $10.00. A typical request, about 1,000 words in and 400 words out, costs $0.0076 on Kimi K3.1 Pro and $0.0076 on Claude Sonnet 5.5.
Prices updated . Benchmarks updated .
| Kimi K3.1 Pro | Claude Sonnet 5.5 | |
|---|---|---|
| Lab | Moonshot | Anthropic |
| You send / 1M | $2.00 | $2.00 |
| It replies / 1M | $10.00 | $10.00 |
| Context | 1.05M | 1M |
| Launched | 2026-10-23 | 2026-09-28 |
| Weights | Closed | Closed |
| Typical request | $0.0076 | $0.0076 |
| ECI | n/a | 166.7 |
| GPQA | n/a | 95.6% |
| ARC-AGI-2 | n/a | 83.9% |
| HLE | n/a | 46.1% |
| AIME | n/a | 100.0% |
| SimpleQA | n/a | 46.5% |
| CritPt | 24.6% | 31.4% |
| Arena | n/a | 1,473 |
| Arena web | 1,695 | 1,770 |
Which is cheaper?
Kimi K3.1 Pro and Claude Sonnet 5.5 cost the same for output tokens, $10.00 per million. Input tokens are $2.00 per million for Kimi K3.1 Pro and $2.00 per million for Claude Sonnet 5.5. A typical request, about 1,000 words in and 400 words out, costs $0.0076 on Kimi K3.1 Pro and $0.0076 on Claude Sonnet 5.5.
Which scores higher?
Claude Sonnet 5.5 scores higher on CritPt: 31.4% against 24.6% for Kimi K3.1 Pro. The score is from the current independent dataset, not from the lab. Lab-reported scores are kept off this comparison. Context windows are 1.05M and 1M. Prices are US dollars per million tokens at current public rates.
Verdict
Claude Sonnet 5.5 scores higher on CritPt (31.4% vs 24.6%). A public token price is missing for at least one model, so this page does not call a cheaper winner. Context is 1.05M for Kimi K3.1 Pro and 1M for Claude Sonnet 5.5. Use the model pages for every score on file, including lab-reported numbers.
FAQ
Which is cheaper, Kimi K3.1 Pro vs Claude Sonnet 5.5?
Kimi K3.1 Pro and Claude Sonnet 5.5 cost the same for output tokens, $10.00 per million. Input tokens are $2.00 per million for Kimi K3.1 Pro and $2.00 per million for Claude Sonnet 5.5. A typical request, about 1,000 words in and 400 words out, costs $0.0076 on Kimi K3.1 Pro and $0.0076 on Claude Sonnet 5.5.
Which scores higher, Kimi K3.1 Pro vs Claude Sonnet 5.5?
Claude Sonnet 5.5 scores higher on CritPt: 31.4% against 24.6% for Kimi K3.1 Pro. The score is from the current independent dataset, not from the lab. Lab-reported scores are kept off this comparison. Context windows are 1.05M and 1M. Prices are US dollars per million tokens at current public rates.
What is the verdict for Kimi K3.1 Pro vs Claude Sonnet 5.5?
Claude Sonnet 5.5 scores higher on CritPt (31.4% vs 24.6%). A public token price is missing for at least one model, so this page does not call a cheaper winner. Context is 1.05M for Kimi K3.1 Pro and 1M for Claude Sonnet 5.5. Use the model pages for every score on file, including lab-reported numbers.
Open this pair in the comparison view
Sources and licenses
- OpenRouter: Prices, context windows, modalities and the model list come from the OpenRouter public API. Data: OpenRouter.
- Vercel AI Gateway: The no-training flag comes from the Vercel AI Gateway model list.
- models.dev: Lab launch dates, open-weights flags and knowledge cutoffs come from models.dev. Copyright (c) 2025 models.dev, MIT License.
- Epoch AI: Independent benchmark scores and the Epoch Capabilities Index (ECI) come from Epoch AI's Benchmarking Hub, used under CC BY 4.0. Epoch AI, Capabilities & benchmarking, epoch.ai/benchmarks. Scores Epoch marks as external keep their original license, and the source is named on each score.
- LMArena: Arena Elo (text, webdev and vision) comes from the LMArena leaderboard dataset (lmarena-ai/leaderboard-dataset), CC BY 4.0, leaderboard date 2026-10-28.
- Lab-reported scores, when an editor has added them, are the lab's own numbers. Each one links to the source and is labeled lab-reported. They are not used to rank the lists.
- What a score measures: the benchmark guide.