High-volume, cost-sensitive work
Either one
Both cost $4.00 per million tokens on a typical mix of three input tokens for every output token.
GPT-6.1 Sol Pro vs Kimi K3.1 Pro: price, context and capabilities
Choose GPT-6.1 Sol Pro for reused prompts and documents (RAG, agents). Choose Kimi K3.1 Pro for the latest release.
In short
- Both cost the same at the headline price ($4.00 / 1M tokens).
- GPT-6.1 Sol Pro reads more per request: 1.05M tokens against 1.05M.
- Kimi K3.1 Pro is the newer model (Oct 23, 2026, against Sep 29, 2026).
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Reused prompts and documents (RAG, agents)
Choose GPT-6.1 Sol Pro
GPT-6.1 Sol Pro charges $0.10 per million cached input tokens, against $0.20 for Kimi K3.1 Pro.
Latest release
Choose Kimi K3.1 Pro
Kimi K3.1 Pro is the newer release (Oct 23, 2026, against Sep 29, 2026 for GPT-6.1 Sol Pro).
Monthly cost at three volumes
| Volume | GPT-6.1 Sol Pro | Kimi K3.1 Pro | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $4.50 | $4.50 | = |
| Production: 20M input, 5M output tokens | $90.00 | $90.00 | = |
| Scale: 500M input, 100M output tokens | $2,000 | $2,000 | = |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| GPT-6.1 Sol Pro | Kimi K3.1 Pro | |
|---|---|---|
| Provider | OpenAI | Moonshot AI |
| Category | Language models | Language models |
| Status | Generally available | Generally available |
| Headline price | $4.00 / 1M tokens | $4.00 / 1M tokens |
| Input | $2.00 / 1M tokens | $2.00 / 1M tokens |
| Output | $10.00 / 1M tokens | $10.00 / 1M tokens |
| Cached input | $0.10 / 1M tokens | $0.20 / 1M tokens |
| Context window | 1.05M | 1.05M |
| Max output | 128k | 944k |
| Released | Sep 29, 2026 | Oct 23, 2026 |
| Knowledge cutoff | No data | No data |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching | Vision, Reasoning, Tool calling, Structured output, Prompt caching |
| API model id | gpt-6.1-sol-pro | kimi-k3.1-pro |
Frequently asked questions
Should I choose GPT-6.1 Sol Pro or Kimi K3.1 Pro?
Choose GPT-6.1 Sol Pro for reused prompts and documents (RAG, agents). Choose Kimi K3.1 Pro for the latest release.
Which is cheaper, GPT-6.1 Sol Pro or Kimi K3.1 Pro?
Both cost the same at the headline price ($4.00 / 1M tokens).
Which has the larger context window, GPT-6.1 Sol Pro or Kimi K3.1 Pro?
GPT-6.1 Sol Pro reads more per request: 1.05M tokens against 1.05M.
What is the difference between GPT-6.1 Sol Pro and Kimi K3.1 Pro?
GPT-6.1 Sol Pro is made by OpenAI and Kimi K3.1 Pro by Moonshot AI. Both cost the same at the headline price ($4.00 / 1M tokens). GPT-6.1 Sol Pro reads more per request: 1.05M tokens against 1.05M. Kimi K3.1 Pro is the newer model (Oct 23, 2026, against Sep 29, 2026).
How much do GPT-6.1 Sol Pro and Kimi K3.1 Pro cost per month?
At 20 million input and 5 million output tokens a month, GPT-6.1 Sol Pro costs $90.00 and Kimi K3.1 Pro costs $90.00, at standard rates.
Which is newer, GPT-6.1 Sol Pro or Kimi K3.1 Pro?
Kimi K3.1 Pro was released on Oct 23, 2026 and GPT-6.1 Sol Pro on Sep 29, 2026.