o4 Reasoning vs o4 Turbo: which model should you choose?
We compared o4 Reasoning and o4 Turbo on price, context window and 12 benchmarks. o4 Reasoning has the stronger average benchmark score; o4 Turbo is cheaper on a blended 3:1 basis.
o4 Reasoning
o4 Reasoning is a frontier model from OpenAI. It offers a 1,000,000-token context window, costs $19.69 per million input tokens and $103.53 per million output tokens, and averages 87.5 across the index's benchmark suite.
- Input
- $19.69 / 1M
- Output
- $103.53 / 1M
- Context
- 1,000,000
- Avg score
- 87.5
- Open weights
- No
o4 Turbo
o4 Turbo is a frontier model from OpenAI. It offers a 2,000,000-token context window, costs $19.34 per million input tokens and $82.19 per million output tokens, and averages 86.6 across the index's benchmark suite.
- Input
- $19.34 / 1M
- Output
- $82.19 / 1M
- Context
- 2,000,000
- Avg score
- 86.6
- Open weights
- No
Specification comparison
| Spec | o4 Reasoning | o4 Turbo | Edge |
|---|---|---|---|
| Input price / 1M | $19.69 | $19.34 | B |
| Output price / 1M | $103.53 | $82.19 | B |
| Context window | 1,000,000 | 2,000,000 | B |
| Max output | 128,000 | 8,192 | A |
| Average score | 87.5 | 86.6 | A |
| Arena Elo | 1472.2 | 1468.1 | A |
| Open weights | No | No | Tie |
Benchmark comparison
o4 Reasoning wins 8, o4 Turbo wins 4, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | o4 Reasoning | o4 Turbo | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 86.1 | 88.1 | 2.0 | o4 Turbo |
| GPQA Diamond | 84.0 | 84.8 | 0.8 | o4 Turbo |
| SWE-bench Verified | 76.4 | 78.4 | 2.0 | o4 Turbo |
| HumanEval | 90.2 | 91.0 | 0.8 | o4 Turbo |
| MATH-500 | 94.8 | 91.7 | 3.1 | o4 Reasoning |
| AIME 2025 | 90.3 | 85.9 | 4.4 | o4 Reasoning |
| LiveCodeBench | 83.4 | 80.1 | 3.3 | o4 Reasoning |
| IFEval | 94.5 | 92.6 | 1.9 | o4 Reasoning |
| TruthfulQA | 89.0 | 88.8 | 0.2 | o4 Reasoning |
| HellaSwag | 92.4 | 91.3 | 1.1 | o4 Reasoning |
| MMMU | 81.8 | 79.6 | 2.2 | o4 Reasoning |
| Arena Elo | 1472.2 | 1468.1 | 4.1 | o4 Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, o4 Reasoning costs about $40.65 per million tokens and o4 Turbo costs about $35.05. o4 Turbo is roughly 14% cheaper than o4 Reasoning. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
o4 Turbo has the larger context window at 2,000,000 tokens, compared with 1,000,000 for o4 Reasoning. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, o4 Reasoning wins 8, o4 Turbo wins 4, and 0 are tied. On the index average, o4 Reasoning leads o4 Turbo by 0.9 points (87.5 versus 86.6).
The price picture favours o4 Turbo. The context picture favours o4 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 o4 Reasoning for quality-sensitive work and o4 Turbo for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.
Choose o4 Reasoning if
- You want the higher average benchmark score in this index.
- You need the larger 128,000-token output limit.
Choose o4 Turbo if
- Unit cost matters and you want the cheaper blended price.
- You need the larger 2,000,000-token context window.
FAQ
Is o4 Reasoning better than o4 Turbo?
On the index average, o4 Reasoning leads o4 Turbo by 0.9 points (87.5 versus 86.6). The better choice depends on price, context and your task. o4 Reasoning wins 8 benchmarks, o4 Turbo wins 4.
Which is cheaper, o4 Reasoning or o4 Turbo?
o4 Turbo is cheaper on a blended 3:1 basis at about $35.05 per million tokens, versus $40.65 for o4 Reasoning.
Which has the larger context window?
o4 Turbo has the larger context window at 2,000,000 tokens. o4 Reasoning has 1,000,000 tokens.
Are these models open weights?
o4 Reasoning is proprietary; o4 Turbo is proprietary.
Which should I choose for production?
If you need a single default, start with o4 Reasoning for quality-sensitive work and o4 Turbo for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.