Claude 3.7 Sonnet Reasoning vs o3 Turbo: which model should you choose?
We compared Claude 3.7 Sonnet Reasoning and o3 Turbo on price, context window and 12 benchmarks. Claude 3.7 Sonnet Reasoning has the stronger average benchmark score; Claude 3.7 Sonnet Reasoning is cheaper on a blended 3:1 basis.
Claude 3.7 Sonnet Reasoning
Claude 3.7 Sonnet Reasoning is a frontier model from Anthropic. It offers a 128,000-token context window, costs $16.30 per million input tokens and $77.62 per million output tokens, and averages 83.7 across the index's benchmark suite.
- Input
- $16.30 / 1M
- Output
- $77.62 / 1M
- Context
- 128,000
- Avg score
- 83.7
- 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 | Claude 3.7 Sonnet Reasoning | o3 Turbo | Edge |
|---|---|---|---|
| Input price / 1M | $16.30 | $16.63 | A |
| Output price / 1M | $77.62 | $83.71 | A |
| Context window | 128,000 | 200,000 | B |
| Max output | 128,000 | 4,096 | A |
| Average score | 83.7 | 83.4 | A |
| Arena Elo | 1464.4 | 1456.2 | A |
| Open weights | No | No | Tie |
Benchmark comparison
Claude 3.7 Sonnet Reasoning wins 7, o3 Turbo wins 5, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude 3.7 Sonnet Reasoning | o3 Turbo | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 86.4 | 82.7 | 3.7 | Claude 3.7 Sonnet Reasoning |
| GPQA Diamond | 81.3 | 77.7 | 3.6 | Claude 3.7 Sonnet Reasoning |
| SWE-bench Verified | 71.0 | 70.7 | 0.3 | Claude 3.7 Sonnet Reasoning |
| HumanEval | 89.2 | 87.4 | 1.8 | Claude 3.7 Sonnet Reasoning |
| MATH-500 | 90.3 | 90.6 | 0.3 | o3 Turbo |
| AIME 2025 | 79.8 | 83.0 | 3.2 | o3 Turbo |
| LiveCodeBench | 79.6 | 80.7 | 1.1 | o3 Turbo |
| IFEval | 90.1 | 89.1 | 1.0 | Claude 3.7 Sonnet Reasoning |
| TruthfulQA | 86.2 | 83.6 | 2.6 | Claude 3.7 Sonnet Reasoning |
| HellaSwag | 90.4 | 91.8 | 1.4 | o3 Turbo |
| MMMU | 76.5 | 79.7 | 3.2 | o3 Turbo |
| Arena Elo | 1464.4 | 1456.2 | 8.2 | Claude 3.7 Sonnet Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, Claude 3.7 Sonnet Reasoning costs about $31.63 per million tokens and o3 Turbo costs about $33.40. Claude 3.7 Sonnet Reasoning is roughly 5% cheaper than o3 Turbo. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
o3 Turbo has the larger context window at 200,000 tokens, compared with 128,000 for Claude 3.7 Sonnet Reasoning. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude 3.7 Sonnet Reasoning wins 7, o3 Turbo wins 5, and 0 are tied. On the index average, Claude 3.7 Sonnet Reasoning leads o3 Turbo by 0.3 points (83.7 versus 83.4).
The price picture favours Claude 3.7 Sonnet Reasoning. The context picture favours o3 Turbo. 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 Claude 3.7 Sonnet Reasoning for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Claude 3.7 Sonnet Reasoning 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 128,000-token output limit.
Choose o3 Turbo if
- You need the larger 200,000-token context window.
FAQ
Is Claude 3.7 Sonnet Reasoning better than o3 Turbo?
On the index average, Claude 3.7 Sonnet Reasoning leads o3 Turbo by 0.3 points (83.7 versus 83.4). The better choice depends on price, context and your task. Claude 3.7 Sonnet Reasoning wins 7 benchmarks, o3 Turbo wins 5.
Which is cheaper, Claude 3.7 Sonnet Reasoning or o3 Turbo?
Claude 3.7 Sonnet Reasoning is cheaper on a blended 3:1 basis at about $31.63 per million tokens, versus $33.40 for o3 Turbo.
Which has the larger context window?
o3 Turbo has the larger context window at 200,000 tokens. Claude 3.7 Sonnet Reasoning has 128,000 tokens.
Are these models open weights?
Claude 3.7 Sonnet Reasoning is proprietary; o3 Turbo is proprietary.
Which should I choose for production?
If you need a single default, start with Claude 3.7 Sonnet Reasoning for quality-sensitive work, and check whether its price holds at your expected volume before committing.