GPT-5.1 vs Kimi K2.6
Detailed pricing comparison and cost analysis.
Updated September 2026
Cost Simulator
| Feature | GPT-5.1 | Kimi K2.6 |
|---|---|---|
| Provider | OpenAI | Moonshot AI |
| Input Price (1M) | $1.25 | $0.95 |
| Output Price (1M) | $10.00 | $4.00 |
| Context Window | 400,000 | 262,144 |
Verdict
GPT-5.1 costs $1.25 per 1M input tokens and $10.00 per 1M output tokens. Kimi K2.6 costs $0.95 per 1M input tokens and $4.00 per 1M output tokens. Kimi K2.6 is 24% cheaper on input tokens than GPT-5.1. For output tokens, Kimi K2.6 is the more affordable option at $4.00/1M vs $10.00.
On context window, GPT-5.1 supports 400,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.
When to choose GPT-5.1
- ✓ You need a larger context window (400,000 tokens)
- ✓ You are already integrated with OpenAI
When to choose Kimi K2.6
- ✓ You need the lowest input token cost ($ 0.95/1M)
- ✓ Your workload is output-heavy — Kimi K2.6 generates text cheaper
- ✓ 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 GPT-5.1 cheaper than Kimi K2.6? ▼
Kimi K2.6 is cheaper on input tokens at $0.95/1M vs $1.25/1M for GPT-5.1 — a 24% saving.
What is the context window of GPT-5.1 vs Kimi K2.6? ▼
GPT-5.1 has a 400,000-token context window. Kimi K2.6 has a 262,144-token context window. GPT-5.1 supports the larger context, suitable for longer documents and agentic workflows.
Which model is better: GPT-5.1 or Kimi K2.6? ▼
The best choice depends on your use case. For cost efficiency on input tokens, Kimi K2.6 is the cheaper option. For maximum context length, GPT-5.1 supports 400,000 tokens. Use the comparison table above to find the right fit for your workload.