GPT-5.1 Vision vs o3 Max: which model should you choose?
We compared GPT-5.1 Vision and o3 Max on price, context window and 12 benchmarks. GPT-5.1 Vision and o3 Max are effectively tied on the index average; GPT-5.1 Vision is cheaper on a blended 3:1 basis.
GPT-5.1 Vision
GPT-5.1 Vision is a frontier model from OpenAI. It offers a 400,000-token context window, costs $17.76 per million input tokens and $80.59 per million output tokens, and averages 84.8 across the index's benchmark suite.
- Input
- $17.76 / 1M
- Output
- $80.59 / 1M
- Context
- 400,000
- Avg score
- 84.8
- Open weights
- No
o3 Max
o3 Max is a frontier model from OpenAI. It offers a 2,000,000-token context window, costs $17.82 per million input tokens and $90.55 per million output tokens, and averages 84.8 across the index's benchmark suite.
- Input
- $17.82 / 1M
- Output
- $90.55 / 1M
- Context
- 2,000,000
- Avg score
- 84.8
- Open weights
- No
Specification comparison
| Spec | GPT-5.1 Vision | o3 Max | Edge |
|---|---|---|---|
| Input price / 1M | $17.76 | $17.82 | A |
| Output price / 1M | $80.59 | $90.55 | A |
| Context window | 400,000 | 2,000,000 | B |
| Max output | 16,384 | 128,000 | B |
| Average score | 84.8 | 84.8 | Tie |
| Arena Elo | 1462.4 | 1465.2 | B |
| Open weights | No | No | Tie |
Benchmark comparison
GPT-5.1 Vision wins 6, o3 Max wins 6, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | GPT-5.1 Vision | o3 Max | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 85.5 | 84.9 | 0.6 | GPT-5.1 Vision |
| GPQA Diamond | 78.7 | 82.7 | 4.0 | o3 Max |
| SWE-bench Verified | 73.6 | 71.8 | 1.8 | GPT-5.1 Vision |
| HumanEval | 89.6 | 89.8 | 0.2 | o3 Max |
| MATH-500 | 89.1 | 87.0 | 2.1 | GPT-5.1 Vision |
| AIME 2025 | 82.4 | 86.2 | 3.8 | o3 Max |
| LiveCodeBench | 77.8 | 76.4 | 1.4 | GPT-5.1 Vision |
| IFEval | 92.7 | 92.5 | 0.2 | GPT-5.1 Vision |
| TruthfulQA | 86.9 | 87.3 | 0.4 | o3 Max |
| HellaSwag | 92.1 | 93.4 | 1.3 | o3 Max |
| MMMU | 83.9 | 80.8 | 3.1 | GPT-5.1 Vision |
| Arena Elo | 1462.4 | 1465.2 | 2.8 | o3 Max |
Price analysis
On a blended 3:1 input-to-output basis, GPT-5.1 Vision costs about $33.47 per million tokens and o3 Max costs about $36.00. GPT-5.1 Vision is roughly 7% cheaper than o3 Max. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
o3 Max has the larger context window at 2,000,000 tokens, compared with 400,000 for GPT-5.1 Vision. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, GPT-5.1 Vision wins 6, o3 Max wins 6, and 0 are tied. The two models are effectively tied on the index average at 84.8.
The price picture favours GPT-5.1 Vision. The context picture favours o3 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 Vision if cost is the constraint and o3 Max if context is the constraint. Test both on a sample of your own traffic before committing.
Choose GPT-5.1 Vision if
- Unit cost matters and you want the cheaper blended price.
Choose o3 Max if
- You need the larger 2,000,000-token context window.
- You need the larger 128,000-token output limit.
FAQ
Is GPT-5.1 Vision better than o3 Max?
The two models are effectively tied on the index average at 84.8. The better choice depends on price, context and your task. GPT-5.1 Vision wins 6 benchmarks, o3 Max wins 6.
Which is cheaper, GPT-5.1 Vision or o3 Max?
GPT-5.1 Vision is cheaper on a blended 3:1 basis at about $33.47 per million tokens, versus $36.00 for o3 Max.
Which has the larger context window?
o3 Max has the larger context window at 2,000,000 tokens. GPT-5.1 Vision has 400,000 tokens.
Are these models open weights?
GPT-5.1 Vision is proprietary; o3 Max is proprietary.
Which should I choose for production?
If you need a single default, start with GPT-5.1 Vision if cost is the constraint and o3 Max if context is the constraint. Test both on a sample of your own traffic before committing.