Gemini 3 Pro Max vs GPT-5.1 Pro: which model should you choose?
We compared Gemini 3 Pro Max and GPT-5.1 Pro on price, context window and 12 benchmarks. Gemini 3 Pro Max has the stronger average benchmark score; GPT-5.1 Pro is cheaper on a blended 3:1 basis.
Gemini 3 Pro Max
Gemini 3 Pro Max is a frontier model from Google DeepMind. It offers a 2,000,000-token context window, costs $20.57 per million input tokens and $112.92 per million output tokens, and averages 87.9 across the index's benchmark suite.
- Input
- $20.57 / 1M
- Output
- $112.92 / 1M
- Context
- 2,000,000
- Avg score
- 87.9
- Open weights
- No
GPT-5.1 Pro
GPT-5.1 Pro is a frontier model from OpenAI. It offers a 200,000-token context window, costs $19.77 per million input tokens and $100.32 per million output tokens, and averages 87.8 across the index's benchmark suite.
- Input
- $19.77 / 1M
- Output
- $100.32 / 1M
- Context
- 200,000
- Avg score
- 87.8
- Open weights
- No
Specification comparison
| Spec | Gemini 3 Pro Max | GPT-5.1 Pro | Edge |
|---|---|---|---|
| Input price / 1M | $20.57 | $19.77 | B |
| Output price / 1M | $112.92 | $100.32 | B |
| Context window | 2,000,000 | 200,000 | A |
| Max output | 128,000 | 32,768 | A |
| Average score | 87.9 | 87.8 | A |
| Arena Elo | 1477.5 | 1490.0 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Gemini 3 Pro Max wins 5, GPT-5.1 Pro wins 7, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Gemini 3 Pro Max | GPT-5.1 Pro | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 89.5 | 86.2 | 3.3 | Gemini 3 Pro Max |
| GPQA Diamond | 81.8 | 83.4 | 1.6 | GPT-5.1 Pro |
| SWE-bench Verified | 76.6 | 80.1 | 3.5 | GPT-5.1 Pro |
| HumanEval | 91.9 | 91.1 | 0.8 | Gemini 3 Pro Max |
| MATH-500 | 92.1 | 95.1 | 3.0 | GPT-5.1 Pro |
| AIME 2025 | 89.6 | 90.6 | 1.0 | GPT-5.1 Pro |
| LiveCodeBench | 83.6 | 82.2 | 1.4 | Gemini 3 Pro Max |
| IFEval | 94.7 | 94.8 | 0.1 | GPT-5.1 Pro |
| TruthfulQA | 89.6 | 86.9 | 2.7 | Gemini 3 Pro Max |
| HellaSwag | 92.6 | 93.8 | 1.2 | GPT-5.1 Pro |
| MMMU | 84.4 | 81.6 | 2.8 | Gemini 3 Pro Max |
| Arena Elo | 1477.5 | 1490.0 | 12.5 | GPT-5.1 Pro |
Price analysis
On a blended 3:1 input-to-output basis, Gemini 3 Pro Max costs about $43.66 per million tokens and GPT-5.1 Pro costs about $39.91. GPT-5.1 Pro is roughly 9% cheaper than Gemini 3 Pro Max. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Gemini 3 Pro Max has the larger context window at 2,000,000 tokens, compared with 200,000 for GPT-5.1 Pro. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Gemini 3 Pro Max wins 5, GPT-5.1 Pro wins 7, and 0 are tied. On the index average, Gemini 3 Pro Max leads GPT-5.1 Pro by 0.1 points (87.9 versus 87.8).
The price picture favours GPT-5.1 Pro. The context picture favours Gemini 3 Pro 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 Gemini 3 Pro Max for quality-sensitive work and GPT-5.1 Pro for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.
Choose Gemini 3 Pro Max if
- You want the higher average benchmark score in this index.
- You need the larger 2,000,000-token context window.
- You need the larger 128,000-token output limit.
Choose GPT-5.1 Pro if
- Unit cost matters and you want the cheaper blended price.
FAQ
Is Gemini 3 Pro Max better than GPT-5.1 Pro?
On the index average, Gemini 3 Pro Max leads GPT-5.1 Pro by 0.1 points (87.9 versus 87.8). The better choice depends on price, context and your task. Gemini 3 Pro Max wins 5 benchmarks, GPT-5.1 Pro wins 7.
Which is cheaper, Gemini 3 Pro Max or GPT-5.1 Pro?
GPT-5.1 Pro is cheaper on a blended 3:1 basis at about $39.91 per million tokens, versus $43.66 for Gemini 3 Pro Max.
Which has the larger context window?
Gemini 3 Pro Max has the larger context window at 2,000,000 tokens. GPT-5.1 Pro has 200,000 tokens.
Are these models open weights?
Gemini 3 Pro Max is proprietary; GPT-5.1 Pro is proprietary.
Which should I choose for production?
If you need a single default, start with Gemini 3 Pro Max for quality-sensitive work and GPT-5.1 Pro for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.