Gemini 3 Pro Reasoning vs GPT-5.1 Max: which model should you choose?
We compared Gemini 3 Pro Reasoning and GPT-5.1 Max on price, context window and 12 benchmarks. GPT-5.1 Max has the stronger average benchmark score; Gemini 3 Pro Reasoning is cheaper on a blended 3:1 basis.
Gemini 3 Pro Reasoning
Gemini 3 Pro Reasoning is a frontier model from Google DeepMind. It offers a 200,000-token context window, costs $19.69 per million input tokens and $98.36 per million output tokens, and averages 87.5 across the index's benchmark suite.
- Input
- $19.69 / 1M
- Output
- $98.36 / 1M
- Context
- 200,000
- Avg score
- 87.5
- Open weights
- No
GPT-5.1 Max
GPT-5.1 Max is a frontier model from OpenAI. It offers a 2,000,000-token context window, costs $20.50 per million input tokens and $103.98 per million output tokens, and averages 87.9 across the index's benchmark suite.
- Input
- $20.50 / 1M
- Output
- $103.98 / 1M
- Context
- 2,000,000
- Avg score
- 87.9
- Open weights
- No
Specification comparison
| Spec | Gemini 3 Pro Reasoning | GPT-5.1 Max | Edge |
|---|---|---|---|
| Input price / 1M | $19.69 | $20.50 | A |
| Output price / 1M | $98.36 | $103.98 | A |
| Context window | 200,000 | 2,000,000 | B |
| Max output | 8,192 | 8,192 | Tie |
| Average score | 87.5 | 87.9 | B |
| Arena Elo | 1485.0 | 1478.2 | A |
| Open weights | No | No | Tie |
Benchmark comparison
Gemini 3 Pro Reasoning wins 6, GPT-5.1 Max wins 5, and 1 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Gemini 3 Pro Reasoning | GPT-5.1 Max | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 90.1 | 91.3 | 1.2 | GPT-5.1 Max |
| GPQA Diamond | 83.9 | 86.4 | 2.5 | GPT-5.1 Max |
| SWE-bench Verified | 76.3 | 75.6 | 0.7 | Gemini 3 Pro Reasoning |
| HumanEval | 90.2 | 92.2 | 2.0 | GPT-5.1 Max |
| MATH-500 | 93.3 | 91.3 | 2.0 | Gemini 3 Pro Reasoning |
| AIME 2025 | 88.8 | 88.8 | 0.0 | Tie |
| LiveCodeBench | 82.0 | 80.2 | 1.8 | Gemini 3 Pro Reasoning |
| IFEval | 93.8 | 92.2 | 1.6 | Gemini 3 Pro Reasoning |
| TruthfulQA | 90.3 | 91.1 | 0.8 | GPT-5.1 Max |
| HellaSwag | 93.5 | 93.1 | 0.4 | Gemini 3 Pro Reasoning |
| MMMU | 80.8 | 85.1 | 4.3 | GPT-5.1 Max |
| Arena Elo | 1485.0 | 1478.2 | 6.8 | Gemini 3 Pro Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, Gemini 3 Pro Reasoning costs about $39.36 per million tokens and GPT-5.1 Max costs about $41.37. Gemini 3 Pro Reasoning is roughly 5% cheaper than GPT-5.1 Max. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
GPT-5.1 Max has the larger context window at 2,000,000 tokens, compared with 200,000 for Gemini 3 Pro Reasoning. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Gemini 3 Pro Reasoning wins 6, GPT-5.1 Max wins 5, and 1 are tied. On the index average, GPT-5.1 Max leads Gemini 3 Pro Reasoning by 0.4 points (87.9 versus 87.5).
The price picture favours Gemini 3 Pro Reasoning. The context picture favours GPT-5.1 Max. Those two dimensions often matter more than a few benchmark points once a model is good enough for the task.
If you need a single default, start with GPT-5.1 Max for quality-sensitive work and Gemini 3 Pro Reasoning for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.
Choose Gemini 3 Pro Reasoning if
- Unit cost matters and you want the cheaper blended price.
Choose GPT-5.1 Max if
- You want the higher average benchmark score in this index.
- You need the larger 2,000,000-token context window.
FAQ
Is Gemini 3 Pro Reasoning better than GPT-5.1 Max?
On the index average, GPT-5.1 Max leads Gemini 3 Pro Reasoning by 0.4 points (87.9 versus 87.5). The better choice depends on price, context and your task. Gemini 3 Pro Reasoning wins 6 benchmarks, GPT-5.1 Max wins 5.
Which is cheaper, Gemini 3 Pro Reasoning or GPT-5.1 Max?
Gemini 3 Pro Reasoning is cheaper on a blended 3:1 basis at about $39.36 per million tokens, versus $41.37 for GPT-5.1 Max.
Which has the larger context window?
GPT-5.1 Max has the larger context window at 2,000,000 tokens. Gemini 3 Pro Reasoning has 200,000 tokens.
Are these models open weights?
Gemini 3 Pro Reasoning is proprietary; GPT-5.1 Max is proprietary.
Which should I choose for production?
If you need a single default, start with GPT-5.1 Max for quality-sensitive work and Gemini 3 Pro Reasoning for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.