Grok 3 Reasoning vs o3 Turbo: which model should you choose?
We compared Grok 3 Reasoning and o3 Turbo on price, context window and 12 benchmarks. o3 Turbo has the stronger average benchmark score; Grok 3 Reasoning is cheaper on a blended 3:1 basis.
Grok 3 Reasoning
Grok 3 Reasoning is a frontier model from xAI. It offers a 200,000-token context window, costs $16.07 per million input tokens and $74.65 per million output tokens, and averages 82.9 across the index's benchmark suite.
- Input
- $16.07 / 1M
- Output
- $74.65 / 1M
- Context
- 200,000
- Avg score
- 82.9
- Open weights
- No
o3 Turbo
o3 Turbo is a frontier model from OpenAI. It offers a 200,000-token context window, costs $16.63 per million input tokens and $83.71 per million output tokens, and averages 83.4 across the index's benchmark suite.
- Input
- $16.63 / 1M
- Output
- $83.71 / 1M
- Context
- 200,000
- Avg score
- 83.4
- Open weights
- No
Specification comparison
| Spec | Grok 3 Reasoning | o3 Turbo | Edge |
|---|---|---|---|
| Input price / 1M | $16.07 | $16.63 | A |
| Output price / 1M | $74.65 | $83.71 | A |
| Context window | 200,000 | 200,000 | Tie |
| Max output | 16,384 | 4,096 | A |
| Average score | 82.9 | 83.4 | B |
| Arena Elo | 1448.0 | 1456.2 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Grok 3 Reasoning wins 4, o3 Turbo wins 8, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Grok 3 Reasoning | o3 Turbo | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 84.5 | 82.7 | 1.8 | Grok 3 Reasoning |
| GPQA Diamond | 77.3 | 77.7 | 0.4 | o3 Turbo |
| SWE-bench Verified | 74.0 | 70.7 | 3.3 | Grok 3 Reasoning |
| HumanEval | 88.5 | 87.4 | 1.1 | Grok 3 Reasoning |
| MATH-500 | 90.2 | 90.6 | 0.4 | o3 Turbo |
| AIME 2025 | 78.2 | 83.0 | 4.8 | o3 Turbo |
| LiveCodeBench | 76.5 | 80.7 | 4.2 | o3 Turbo |
| IFEval | 90.2 | 89.1 | 1.1 | Grok 3 Reasoning |
| TruthfulQA | 83.4 | 83.6 | 0.2 | o3 Turbo |
| HellaSwag | 89.7 | 91.8 | 2.1 | o3 Turbo |
| MMMU | 79.4 | 79.7 | 0.3 | o3 Turbo |
| Arena Elo | 1448.0 | 1456.2 | 8.2 | o3 Turbo |
Price analysis
On a blended 3:1 input-to-output basis, Grok 3 Reasoning costs about $30.72 per million tokens and o3 Turbo costs about $33.40. Grok 3 Reasoning is roughly 8% cheaper than o3 Turbo. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Both models list a 200,000-token context window. That is enough for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Grok 3 Reasoning wins 4, o3 Turbo wins 8, and 0 are tied. On the index average, o3 Turbo leads Grok 3 Reasoning by 0.5 points (83.4 versus 82.9).
The price picture favours Grok 3 Reasoning. The context picture is effectively a tie. 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 o3 Turbo for quality-sensitive work and Grok 3 Reasoning for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.
Choose Grok 3 Reasoning if
- Unit cost matters and you want the cheaper blended price.
- You need the larger 16,384-token output limit.
Choose o3 Turbo if
- You want the higher average benchmark score in this index.
FAQ
Is Grok 3 Reasoning better than o3 Turbo?
On the index average, o3 Turbo leads Grok 3 Reasoning by 0.5 points (83.4 versus 82.9). The better choice depends on price, context and your task. Grok 3 Reasoning wins 4 benchmarks, o3 Turbo wins 8.
Which is cheaper, Grok 3 Reasoning or o3 Turbo?
Grok 3 Reasoning is cheaper on a blended 3:1 basis at about $30.72 per million tokens, versus $33.40 for o3 Turbo.
Which has the larger context window?
Both models list a 200,000-token context window.
Are these models open weights?
Grok 3 Reasoning is proprietary; o3 Turbo is proprietary.
Which should I choose for production?
If you need a single default, start with o3 Turbo for quality-sensitive work and Grok 3 Reasoning for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.