Hardest reasoning tasks
Either one
They are practically level on the Artificial Analysis Intelligence Index (42.1 and 43.6).
GPT-5.6 Terra vs Kimi K3: price, context and capabilities
Choose GPT-5.6 Terra for images as input. Choose Kimi K3 for reasoning over long documents and the latest release.
In short
- A price comparison is not possible: one of them has no comparable published price.
- GPT-5.6 Terra reads more per request: 1.05M tokens against 1M.
- Only GPT-5.6 Terra offers vision, structured output, prompt caching, batch api.
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Reasoning over long documents
Choose Kimi K3
Kimi K3 scores 88.7% on Long-context reasoning (AA-LCR), against 83% for GPT-5.6 Terra.
Images as input
Choose GPT-5.6 Terra
GPT-5.6 Terra accepts images as input; Kimi K3 does not.
Latest release
Choose Kimi K3
Kimi K3 is the newer release (Jul 16, 2026, against Jul 9, 2026 for GPT-5.6 Terra).
Specifications side by side
| GPT-5.6 Terra | Kimi K3 | |
|---|---|---|
| Provider | OpenAI | Moonshot AI |
| Category | Language models | Language models |
| Status | Generally available | Generally available |
| Headline price | $4.50 / 1M tokens | No data |
| Input | $2.00 / 1M tokens | No data |
| Output | $12.00 / 1M tokens | No data |
| Cached input | $0.20 / 1M tokens | No data |
| Context window | 1.05M | 1M |
| Max output | 128k | No data |
| Released | Jul 9, 2026 | Jul 16, 2026 |
| Knowledge cutoff | February 2026 | No data |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API | Reasoning, Tool calling |
| API model id | gpt-5.6-terra | kimi-k3 |
Benchmarks side by side
Leader in bold.
| Benchmark | GPT-5.6 Terra | Kimi K3 |
|---|---|---|
| Intelligence Index | 42.1 | 43.6 |
| SciCode | 55% | 59.5% |
| GPQA Diamond | 92.5% | 93.5% |
| Humanity's Last Exam | 42.9% | 46.9% |
| MMMU-Pro (visual reasoning) | 80.7% | 80.5% |
| Long-context reasoning (AA-LCR) | 83% | 88.7% |
| Terminal-Bench Hard | 57.6% | No data |
| IFBench (instruction following) | 71.2% | No data |
| τ²-Bench (agentic tool use) | 86.3% | No data |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Frequently asked questions
Should I choose GPT-5.6 Terra or Kimi K3?
Choose GPT-5.6 Terra for images as input. Choose Kimi K3 for reasoning over long documents and the latest release.
Which is cheaper, GPT-5.6 Terra or Kimi K3?
A price comparison is not possible: one of them has no comparable published price.
Which has the larger context window, GPT-5.6 Terra or Kimi K3?
GPT-5.6 Terra reads more per request: 1.05M tokens against 1M.
What is the difference between GPT-5.6 Terra and Kimi K3?
GPT-5.6 Terra is made by OpenAI and Kimi K3 by Moonshot AI. A price comparison is not possible: one of them has no comparable published price. GPT-5.6 Terra reads more per request: 1.05M tokens against 1M. Only GPT-5.6 Terra offers vision, structured output, prompt caching, batch api.
Which is newer, GPT-5.6 Terra or Kimi K3?
Kimi K3 was released on Jul 16, 2026 and GPT-5.6 Terra on Jul 9, 2026.