Gemini 3 Flash Max vs o3: which model should you choose?
We compared Gemini 3 Flash Max and o3 on price, context window and 12 benchmarks. Gemini 3 Flash Max has the stronger average benchmark score; Gemini 3 Flash Max is cheaper on a blended 3:1 basis.
Gemini 3 Flash Max
Gemini 3 Flash Max is a frontier model from Google DeepMind. It offers a 1,000,000-token context window, costs $17.43 per million input tokens and $63.42 per million output tokens, and averages 85.0 across the index's benchmark suite.
- Input
- $17.43 / 1M
- Output
- $63.42 / 1M
- Context
- 1,000,000
- Avg score
- 85.0
- Open weights
- No
o3
o3 is a frontier model from OpenAI. It offers a 400,000-token context window, costs $16.80 per million input tokens and $81.80 per million output tokens, and averages 84.5 across the index's benchmark suite.
- Input
- $16.80 / 1M
- Output
- $81.80 / 1M
- Context
- 400,000
- Avg score
- 84.5
- Open weights
- No
Specification comparison
| Spec | Gemini 3 Flash Max | o3 | Edge |
|---|---|---|---|
| Input price / 1M | $17.43 | $16.80 | B |
| Output price / 1M | $63.42 | $81.80 | A |
| Context window | 1,000,000 | 400,000 | A |
| Max output | 65,536 | 4,096 | A |
| Average score | 85.0 | 84.5 | A |
| Arena Elo | 1448.5 | 1449.0 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Gemini 3 Flash Max wins 7, o3 wins 5, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Gemini 3 Flash Max | o3 | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 87.8 | 86.9 | 0.9 | Gemini 3 Flash Max |
| GPQA Diamond | 80.9 | 78.3 | 2.6 | Gemini 3 Flash Max |
| SWE-bench Verified | 73.8 | 72.9 | 0.9 | Gemini 3 Flash Max |
| HumanEval | 88.5 | 89.8 | 1.3 | o3 |
| MATH-500 | 88.6 | 87.9 | 0.7 | Gemini 3 Flash Max |
| AIME 2025 | 86.7 | 84.4 | 2.3 | Gemini 3 Flash Max |
| LiveCodeBench | 78.3 | 80.7 | 2.4 | o3 |
| IFEval | 91.3 | 88.7 | 2.6 | Gemini 3 Flash Max |
| TruthfulQA | 87.1 | 84.6 | 2.5 | Gemini 3 Flash Max |
| HellaSwag | 91.1 | 92.7 | 1.6 | o3 |
| MMMU | 81.0 | 82.3 | 1.3 | o3 |
| Arena Elo | 1448.5 | 1449.0 | 0.5 | o3 |
Price analysis
On a blended 3:1 input-to-output basis, Gemini 3 Flash Max costs about $28.93 per million tokens and o3 costs about $33.05. Gemini 3 Flash Max is roughly 12% cheaper than o3. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Gemini 3 Flash Max has the larger context window at 1,000,000 tokens, compared with 400,000 for o3. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Gemini 3 Flash Max wins 7, o3 wins 5, and 0 are tied. On the index average, Gemini 3 Flash Max leads o3 by 0.5 points (85.0 versus 84.5).
The price picture favours Gemini 3 Flash Max. The context picture favours Gemini 3 Flash 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 Flash Max for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Gemini 3 Flash Max if
- You want the higher average benchmark score in this index.
- Unit cost matters and you want the cheaper blended price.
- You need the larger 1,000,000-token context window.
- You need the larger 65,536-token output limit.
Choose o3 if
- You prefer OpenAI's tooling or already use it.
FAQ
Is Gemini 3 Flash Max better than o3?
On the index average, Gemini 3 Flash Max leads o3 by 0.5 points (85.0 versus 84.5). The better choice depends on price, context and your task. Gemini 3 Flash Max wins 7 benchmarks, o3 wins 5.
Which is cheaper, Gemini 3 Flash Max or o3?
Gemini 3 Flash Max is cheaper on a blended 3:1 basis at about $28.93 per million tokens, versus $33.05 for o3.
Which has the larger context window?
Gemini 3 Flash Max has the larger context window at 1,000,000 tokens. o3 has 400,000 tokens.
Are these models open weights?
Gemini 3 Flash Max is proprietary; o3 is proprietary.
Which should I choose for production?
If you need a single default, start with Gemini 3 Flash Max for quality-sensitive work, and check whether its price holds at your expected volume before committing.