High-volume, cost-sensitive work
Either one
Both cost $4.50 per million tokens on a typical mix of three input tokens for every output token.
Gemini 3.1 Pro vs GPT-5.6 Terra: price, context and capabilities
Choose Gemini 3.1 Pro for tool use and support agents. Choose GPT-5.6 Terra for the hardest reasoning tasks, agentic coding and the latest release.
In short
- Both cost the same at the headline price ($4.50 / 1M tokens).
- GPT-5.6 Terra reads more per request: 1.05M tokens against 1.05M.
- GPT-5.6 Terra is the newer model (Jul 9, 2026, against February 2026).
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Hardest reasoning tasks
Choose GPT-5.6 Terra
GPT-5.6 Terra scores 42.1 on the Artificial Analysis Intelligence Index, against 29.7 for Gemini 3.1 Pro.
Agentic coding
Choose GPT-5.6 Terra
GPT-5.6 Terra scores 57.6% on Terminal-Bench Hard, against 53.8% for Gemini 3.1 Pro.
Tool use and support agents
Choose Gemini 3.1 Pro
Gemini 3.1 Pro scores 95.6% on τ²-Bench (agentic tool use), against 86.3% for GPT-5.6 Terra.
Reasoning over long documents
Either one
They are practically level on Long-context reasoning (AA-LCR) (82% and 83%).
Latest release
Choose GPT-5.6 Terra
GPT-5.6 Terra is the newer release (Jul 9, 2026, against February 2026 for Gemini 3.1 Pro).
Monthly cost at three volumes
| Volume | Gemini 3.1 Pro | GPT-5.6 Terra | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $5.00 | $5.00 | = |
| Production: 20M input, 5M output tokens | $100.00 | $100.00 | = |
| Scale: 500M input, 100M output tokens | $2,200 | $2,200 | = |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| Gemini 3.1 Pro | GPT-5.6 Terra | |
|---|---|---|
| Provider | OpenAI | |
| Category | Language models | Language models |
| Status | Preview | Generally available |
| Headline price | $4.50 / 1M tokens | $4.50 / 1M tokens |
| Input | $2.00 / 1M tokens | $2.00 / 1M tokens |
| Output | $12.00 / 1M tokens | $12.00 / 1M tokens |
| Cached input | $0.20 / 1M tokens | $0.20 / 1M tokens |
| Context window | 1.05M | 1.05M |
| Max output | 66k | 128k |
| Released | February 2026 | Jul 9, 2026 |
| Knowledge cutoff | No data | February 2026 |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API |
| API model id | gemini-3.1-pro-preview | gpt-5.6-terra |
Benchmarks side by side
Leader in bold.
| Benchmark | Gemini 3.1 Pro | GPT-5.6 Terra |
|---|---|---|
| Intelligence Index | 29.7 | 42.1 |
| Terminal-Bench Hard | 53.8% | 57.6% |
| SciCode | 58.7% | 55% |
| GPQA Diamond | 94.1% | 92.5% |
| Humanity's Last Exam | 47% | 42.9% |
| IFBench (instruction following) | 77.1% | 71.2% |
| τ²-Bench (agentic tool use) | 95.6% | 86.3% |
| MMMU-Pro (visual reasoning) | 82.4% | 80.7% |
| Long-context reasoning (AA-LCR) | 82% | 83% |
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 Gemini 3.1 Pro or GPT-5.6 Terra?
Choose Gemini 3.1 Pro for tool use and support agents. Choose GPT-5.6 Terra for the hardest reasoning tasks, agentic coding and the latest release.
Which is cheaper, Gemini 3.1 Pro or GPT-5.6 Terra?
Both cost the same at the headline price ($4.50 / 1M tokens).
Which has the larger context window, Gemini 3.1 Pro or GPT-5.6 Terra?
GPT-5.6 Terra reads more per request: 1.05M tokens against 1.05M.
What is the difference between Gemini 3.1 Pro and GPT-5.6 Terra?
Gemini 3.1 Pro is made by Google and GPT-5.6 Terra by OpenAI. Both cost the same at the headline price ($4.50 / 1M tokens). GPT-5.6 Terra reads more per request: 1.05M tokens against 1.05M. GPT-5.6 Terra is the newer model (Jul 9, 2026, against February 2026).
Which is better for coding, Gemini 3.1 Pro or GPT-5.6 Terra?
GPT-5.6 Terra scores 57.6% on Terminal-Bench Hard, against 53.8% for Gemini 3.1 Pro.
How much do Gemini 3.1 Pro and GPT-5.6 Terra cost per month?
At 20 million input and 5 million output tokens a month, Gemini 3.1 Pro costs $100.00 and GPT-5.6 Terra costs $100.00, at standard rates.
Which is newer, Gemini 3.1 Pro or GPT-5.6 Terra?
GPT-5.6 Terra was released on Jul 9, 2026 and Gemini 3.1 Pro on February 2026.