Gemini 3 Pro Reasoning vs o4 Pro: which model should you choose?
We compared Gemini 3 Pro Reasoning and o4 Pro on price, context window and 12 benchmarks. Gemini 3 Pro Reasoning has the stronger average benchmark score; o4 Pro 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
o4 Pro
o4 Pro is a frontier model from OpenAI. It offers a 1,000,000-token context window, costs $19.37 per million input tokens and $70.19 per million output tokens, and averages 87.3 across the index's benchmark suite.
- Input
- $19.37 / 1M
- Output
- $70.19 / 1M
- Context
- 1,000,000
- Avg score
- 87.3
- Open weights
- No
Specification comparison
| Spec | Gemini 3 Pro Reasoning | o4 Pro | Edge |
|---|---|---|---|
| Input price / 1M | $19.69 | $19.37 | B |
| Output price / 1M | $98.36 | $70.19 | B |
| Context window | 200,000 | 1,000,000 | B |
| Max output | 8,192 | 16,384 | B |
| Average score | 87.5 | 87.3 | A |
| Arena Elo | 1485.0 | 1471.2 | A |
| Open weights | No | No | Tie |
Benchmark comparison
Gemini 3 Pro Reasoning wins 7, o4 Pro wins 5, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Gemini 3 Pro Reasoning | o4 Pro | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 90.1 | 87.7 | 2.4 | Gemini 3 Pro Reasoning |
| GPQA Diamond | 83.9 | 82.7 | 1.2 | Gemini 3 Pro Reasoning |
| SWE-bench Verified | 76.3 | 78.5 | 2.2 | o4 Pro |
| HumanEval | 90.2 | 92.1 | 1.9 | o4 Pro |
| MATH-500 | 93.3 | 89.8 | 3.5 | Gemini 3 Pro Reasoning |
| AIME 2025 | 88.8 | 89.9 | 1.1 | o4 Pro |
| LiveCodeBench | 82.0 | 81.8 | 0.2 | Gemini 3 Pro Reasoning |
| IFEval | 93.8 | 90.9 | 2.9 | Gemini 3 Pro Reasoning |
| TruthfulQA | 90.3 | 87.9 | 2.4 | Gemini 3 Pro Reasoning |
| HellaSwag | 93.5 | 94.4 | 0.9 | o4 Pro |
| MMMU | 80.8 | 84.1 | 3.3 | o4 Pro |
| Arena Elo | 1485.0 | 1471.2 | 13.8 | 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 o4 Pro costs about $32.08. o4 Pro is roughly 19% cheaper than Gemini 3 Pro Reasoning. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
o4 Pro has the larger context window at 1,000,000 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 7, o4 Pro wins 5, and 0 are tied. On the index average, Gemini 3 Pro Reasoning leads o4 Pro by 0.2 points (87.5 versus 87.3).
The price picture favours o4 Pro. The context picture favours o4 Pro. 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 Reasoning for quality-sensitive work and o4 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 Reasoning if
- You want the higher average benchmark score in this index.
Choose o4 Pro if
- Unit cost matters and you want the cheaper blended price.
- You need the larger 1,000,000-token context window.
- You need the larger 16,384-token output limit.
FAQ
Is Gemini 3 Pro Reasoning better than o4 Pro?
On the index average, Gemini 3 Pro Reasoning leads o4 Pro by 0.2 points (87.5 versus 87.3). The better choice depends on price, context and your task. Gemini 3 Pro Reasoning wins 7 benchmarks, o4 Pro wins 5.
Which is cheaper, Gemini 3 Pro Reasoning or o4 Pro?
o4 Pro is cheaper on a blended 3:1 basis at about $32.08 per million tokens, versus $39.36 for Gemini 3 Pro Reasoning.
Which has the larger context window?
o4 Pro has the larger context window at 1,000,000 tokens. Gemini 3 Pro Reasoning has 200,000 tokens.
Are these models open weights?
Gemini 3 Pro Reasoning is proprietary; o4 Pro is proprietary.
Which should I choose for production?
If you need a single default, start with Gemini 3 Pro Reasoning for quality-sensitive work and o4 Pro for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.