High-volume, cost-sensitive work
Choose Gemini 3.1 Pro
Gemini 3.1 Pro costs 44% less on a typical mix of three input tokens for every output token ($4.50 against $8.00 per million tokens).
Gemini 3.1 Pro vs GPT-5.6 Sol: price, context and capabilities
Choose Gemini 3.1 Pro for high-volume, cost-sensitive work, writing and code generation, reused prompts and documents (RAG, agents) and tool use and support agents. Choose GPT-5.6 Sol for the hardest reasoning tasks, agentic coding, reasoning over long documents and the latest release.
In short
- Gemini 3.1 Pro is 44% cheaper than GPT-5.6 Sol at the headline price ($4.50 / 1M tokens vs $8.00 / 1M tokens).
- GPT-5.6 Sol reads more per request: 1.05M tokens against 1.05M.
- GPT-5.6 Sol 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.
Writing and code generation
Choose Gemini 3.1 Pro
Gemini 3.1 Pro charges $12.00 per million output tokens, against $20.00 for GPT-5.6 Sol. Output dominates the bill when answers are long.
Reused prompts and documents (RAG, agents)
Choose Gemini 3.1 Pro
Gemini 3.1 Pro charges $0.20 per million cached input tokens, against $0.40 for GPT-5.6 Sol.
Hardest reasoning tasks
Choose GPT-5.6 Sol
GPT-5.6 Sol scores 47 on the Artificial Analysis Intelligence Index, against 29.7 for Gemini 3.1 Pro.
Agentic coding
Choose GPT-5.6 Sol
GPT-5.6 Sol scores 65.9% 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 85.1% for GPT-5.6 Sol.
Reasoning over long documents
Choose GPT-5.6 Sol
GPT-5.6 Sol scores 84% on Long-context reasoning (AA-LCR), against 82% for Gemini 3.1 Pro.
Latest release
Choose GPT-5.6 Sol
GPT-5.6 Sol 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 Sol | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $5.00 | $9.00 | Gemini 3.1 Pro, $4.00 less |
| Production: 20M input, 5M output tokens | $100.00 | $180.00 | Gemini 3.1 Pro, $80.00 less |
| Scale: 500M input, 100M output tokens | $2,200 | $4,000 | Gemini 3.1 Pro, $1,800 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| Gemini 3.1 Pro | GPT-5.6 Sol | |
|---|---|---|
| Provider | OpenAI | |
| Category | Language models | Language models |
| Status | Preview | Generally available |
| Headline price | $4.50 / 1M tokens | $8.00 / 1M tokens |
| Input | $2.00 / 1M tokens | $4.00 / 1M tokens |
| Output | $12.00 / 1M tokens | $20.00 / 1M tokens |
| Cached input | $0.20 / 1M tokens | $0.40 / 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-sol |
Benchmarks side by side
Leader in bold.
| Benchmark | Gemini 3.1 Pro | GPT-5.6 Sol |
|---|---|---|
| Intelligence Index | 29.7 | 47 |
| Terminal-Bench Hard | 53.8% | 65.9% |
| SciCode | 58.7% | 57.1% |
| GPQA Diamond | 94.1% | 94.1% |
| Humanity's Last Exam | 47% | 49.5% |
| IFBench (instruction following) | 77.1% | 72.7% |
| τ²-Bench (agentic tool use) | 95.6% | 85.1% |
| MMMU-Pro (visual reasoning) | 82.4% | 83.4% |
| Long-context reasoning (AA-LCR) | 82% | 84% |
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 Sol?
Choose Gemini 3.1 Pro for high-volume, cost-sensitive work, writing and code generation, reused prompts and documents (RAG, agents) and tool use and support agents. Choose GPT-5.6 Sol for the hardest reasoning tasks, agentic coding, reasoning over long documents and the latest release.
Which is cheaper, Gemini 3.1 Pro or GPT-5.6 Sol?
Gemini 3.1 Pro is 44% cheaper than GPT-5.6 Sol at the headline price ($4.50 / 1M tokens vs $8.00 / 1M tokens).
Which has the larger context window, Gemini 3.1 Pro or GPT-5.6 Sol?
GPT-5.6 Sol reads more per request: 1.05M tokens against 1.05M.
What is the difference between Gemini 3.1 Pro and GPT-5.6 Sol?
Gemini 3.1 Pro is made by Google and GPT-5.6 Sol by OpenAI. Gemini 3.1 Pro is 44% cheaper than GPT-5.6 Sol at the headline price ($4.50 / 1M tokens vs $8.00 / 1M tokens). GPT-5.6 Sol reads more per request: 1.05M tokens against 1.05M. GPT-5.6 Sol is the newer model (Jul 9, 2026, against February 2026).
Which is better for coding, Gemini 3.1 Pro or GPT-5.6 Sol?
GPT-5.6 Sol scores 65.9% on Terminal-Bench Hard, against 53.8% for Gemini 3.1 Pro.
How much do Gemini 3.1 Pro and GPT-5.6 Sol 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 Sol costs $180.00, at standard rates.
Which is newer, Gemini 3.1 Pro or GPT-5.6 Sol?
GPT-5.6 Sol was released on Jul 9, 2026 and Gemini 3.1 Pro on February 2026.