GPT-4.1 Reasoning vs o3: which model should you choose?
We compared GPT-4.1 Reasoning and o3 on price, context window and 12 benchmarks. o3 has the stronger average benchmark score; o3 is cheaper on a blended 3:1 basis.
GPT-4.1 Reasoning
GPT-4.1 Reasoning is a frontier model from OpenAI. It offers a 1,000,000-token context window, costs $16.97 per million input tokens and $82.05 per million output tokens, and averages 83.8 across the index's benchmark suite.
- Input
- $16.97 / 1M
- Output
- $82.05 / 1M
- Context
- 1,000,000
- Avg score
- 83.8
- 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 | GPT-4.1 Reasoning | o3 | Edge |
|---|---|---|---|
| Input price / 1M | $16.97 | $16.80 | B |
| Output price / 1M | $82.05 | $81.80 | B |
| Context window | 1,000,000 | 400,000 | A |
| Max output | 4,096 | 4,096 | Tie |
| Average score | 83.8 | 84.5 | B |
| Arena Elo | 1466.7 | 1449.0 | A |
| Open weights | No | No | Tie |
Benchmark comparison
GPT-4.1 Reasoning wins 5, o3 wins 7, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | GPT-4.1 Reasoning | o3 | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 87.3 | 86.9 | 0.4 | GPT-4.1 Reasoning |
| GPQA Diamond | 77.8 | 78.3 | 0.5 | o3 |
| SWE-bench Verified | 73.1 | 72.9 | 0.2 | GPT-4.1 Reasoning |
| HumanEval | 88.8 | 89.8 | 1.0 | o3 |
| MATH-500 | 89.1 | 87.9 | 1.2 | GPT-4.1 Reasoning |
| AIME 2025 | 82.1 | 84.4 | 2.3 | o3 |
| LiveCodeBench | 80.5 | 80.7 | 0.2 | o3 |
| IFEval | 91.6 | 88.7 | 2.9 | GPT-4.1 Reasoning |
| TruthfulQA | 84.3 | 84.6 | 0.3 | o3 |
| HellaSwag | 89.4 | 92.7 | 3.3 | o3 |
| MMMU | 77.5 | 82.3 | 4.8 | o3 |
| Arena Elo | 1466.7 | 1449.0 | 17.7 | GPT-4.1 Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, GPT-4.1 Reasoning costs about $33.24 per million tokens and o3 costs about $33.05. o3 is roughly 1% cheaper than GPT-4.1 Reasoning. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
GPT-4.1 Reasoning 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, GPT-4.1 Reasoning wins 5, o3 wins 7, and 0 are tied. On the index average, o3 leads GPT-4.1 Reasoning by 0.7 points (84.5 versus 83.8).
The price picture favours o3. The context picture favours GPT-4.1 Reasoning. 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 for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose GPT-4.1 Reasoning if
- You need the larger 1,000,000-token context window.
Choose o3 if
- You want the higher average benchmark score in this index.
- Unit cost matters and you want the cheaper blended price.
FAQ
Is GPT-4.1 Reasoning better than o3?
On the index average, o3 leads GPT-4.1 Reasoning by 0.7 points (84.5 versus 83.8). The better choice depends on price, context and your task. GPT-4.1 Reasoning wins 5 benchmarks, o3 wins 7.
Which is cheaper, GPT-4.1 Reasoning or o3?
o3 is cheaper on a blended 3:1 basis at about $33.05 per million tokens, versus $33.24 for GPT-4.1 Reasoning.
Which has the larger context window?
GPT-4.1 Reasoning has the larger context window at 1,000,000 tokens. o3 has 400,000 tokens.
Are these models open weights?
GPT-4.1 Reasoning is proprietary; o3 is proprietary.
Which should I choose for production?
If you need a single default, start with o3 for quality-sensitive work, and check whether its price holds at your expected volume before committing.