Grok 3 Max vs o3 Pro: which model should you choose?
We compared Grok 3 Max and o3 Pro on price, context window and 12 benchmarks. Grok 3 Max has the stronger average benchmark score; o3 Pro is cheaper on a blended 3:1 basis.
Grok 3 Max
Grok 3 Max is a frontier model from xAI. It offers a 2,000,000-token context window, costs $17.66 per million input tokens and $89.12 per million output tokens, and averages 85.9 across the index's benchmark suite.
- Input
- $17.66 / 1M
- Output
- $89.12 / 1M
- Context
- 2,000,000
- Avg score
- 85.9
- Open weights
- No
o3 Pro
o3 Pro is a frontier model from OpenAI. It offers a 400,000-token context window, costs $17.89 per million input tokens and $81.48 per million output tokens, and averages 85.8 across the index's benchmark suite.
- Input
- $17.89 / 1M
- Output
- $81.48 / 1M
- Context
- 400,000
- Avg score
- 85.8
- Open weights
- No
Specification comparison
| Spec | Grok 3 Max | o3 Pro | Edge |
|---|---|---|---|
| Input price / 1M | $17.66 | $17.89 | A |
| Output price / 1M | $89.12 | $81.48 | B |
| Context window | 2,000,000 | 400,000 | A |
| Max output | 32,768 | 8,192 | A |
| Average score | 85.9 | 85.8 | A |
| Arena Elo | 1475.8 | 1471.9 | A |
| Open weights | No | No | Tie |
Benchmark comparison
Grok 3 Max wins 6, o3 Pro wins 6, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Grok 3 Max | o3 Pro | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 87.3 | 84.3 | 3.0 | Grok 3 Max |
| GPQA Diamond | 80.9 | 78.7 | 2.2 | Grok 3 Max |
| SWE-bench Verified | 73.6 | 76.9 | 3.3 | o3 Pro |
| HumanEval | 91.9 | 90.6 | 1.3 | Grok 3 Max |
| MATH-500 | 91.9 | 92.4 | 0.5 | o3 Pro |
| AIME 2025 | 86.6 | 83.5 | 3.1 | Grok 3 Max |
| LiveCodeBench | 79.7 | 82.4 | 2.7 | o3 Pro |
| IFEval | 92.6 | 90.9 | 1.7 | Grok 3 Max |
| TruthfulQA | 86.7 | 88.4 | 1.7 | o3 Pro |
| HellaSwag | 91.8 | 92.5 | 0.7 | o3 Pro |
| MMMU | 82.3 | 83.1 | 0.8 | o3 Pro |
| Arena Elo | 1475.8 | 1471.9 | 3.9 | Grok 3 Max |
Price analysis
On a blended 3:1 input-to-output basis, Grok 3 Max costs about $35.53 per million tokens and o3 Pro costs about $33.79. o3 Pro is roughly 5% cheaper than Grok 3 Max. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Grok 3 Max has the larger context window at 2,000,000 tokens, compared with 400,000 for o3 Pro. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Grok 3 Max wins 6, o3 Pro wins 6, and 0 are tied. On the index average, Grok 3 Max leads o3 Pro by 0.1 points (85.9 versus 85.8).
The price picture favours o3 Pro. The context picture favours Grok 3 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 Grok 3 Max for quality-sensitive work and o3 Pro for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.
Choose Grok 3 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 32,768-token output limit.
Choose o3 Pro if
- Unit cost matters and you want the cheaper blended price.
FAQ
Is Grok 3 Max better than o3 Pro?
On the index average, Grok 3 Max leads o3 Pro by 0.1 points (85.9 versus 85.8). The better choice depends on price, context and your task. Grok 3 Max wins 6 benchmarks, o3 Pro wins 6.
Which is cheaper, Grok 3 Max or o3 Pro?
o3 Pro is cheaper on a blended 3:1 basis at about $33.79 per million tokens, versus $35.53 for Grok 3 Max.
Which has the larger context window?
Grok 3 Max has the larger context window at 2,000,000 tokens. o3 Pro has 400,000 tokens.
Are these models open weights?
Grok 3 Max is proprietary; o3 Pro is proprietary.
Which should I choose for production?
If you need a single default, start with Grok 3 Max for quality-sensitive work and o3 Pro for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.