Claude Sonnet 5 vs Kimi K3
Detailed pricing comparison and cost analysis.
Updated September 2026
Cost Simulator
| Feature | Claude Sonnet 5 | Kimi K3 |
|---|---|---|
| Provider | Anthropic | Moonshot AI |
| Input Price (1M) | $2.00 | $3.00 |
| Output Price (1M) | $10.00 | $15.00 |
| Context Window | 1,000,000 | 1,000,000 |
Verdict
Claude Sonnet 5 costs $2.00 per 1M input tokens and $10.00 per 1M output tokens. Kimi K3 costs $3.00 per 1M input tokens and $15.00 per 1M output tokens. Claude Sonnet 5 is 33% cheaper on input tokens than Kimi K3. For output tokens, Claude Sonnet 5 is the more affordable option at $10.00/1M vs $15.00.
On context window, Claude Sonnet 5 supports 1,000,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.
When to choose Claude Sonnet 5
- ✓ You need the lowest input token cost ($ 2.00/1M)
- ✓ Your workload is output-heavy — Claude Sonnet 5 generates text cheaper
- ✓ You are already integrated with Anthropic
When to choose Kimi K3
- ✓ You are already integrated with Moonshot AI
Use the calculator above to simulate your specific workload and find the exact break-even point. For most applications, the cheapest model is the one that minimises your total monthly bill given your input-to-output token ratio.
Frequently Asked Questions
Is Claude Sonnet 5 cheaper than Kimi K3? ▼
Claude Sonnet 5 is cheaper on input tokens at $2.00/1M vs $3.00/1M for Kimi K3 — a 33% saving.
What is the context window of Claude Sonnet 5 vs Kimi K3? ▼
Claude Sonnet 5 has a 1,000,000-token context window. Kimi K3 has a 1,000,000-token context window. Claude Sonnet 5 supports the larger context, suitable for longer documents and agentic workflows.
Which model is better: Claude Sonnet 5 or Kimi K3? ▼
The best choice depends on your use case. For cost efficiency on input tokens, Claude Sonnet 5 is the cheaper option. For maximum context length, Claude Sonnet 5 supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.