o3 Reasoning: pricing, context window and benchmarks
o3 Reasoning is a frontier model from OpenAI. It offers a 200,000-token context window, costs $18.07 per million input tokens and $70.65 per million output tokens, and averages 85.3 across the index's benchmark suite.
Pricing
o3 Reasoning costs $18.07 per million input tokens and $70.65 per million output tokens. A blended 3:1 input-to-output mix works out to about $31.22 per million tokens. Cached input is listed at $2.50 per million tokens.
| Item | Price | Notes |
|---|---|---|
| Input | $18.07 | per 1M tokens |
| Output | $70.65 | per 1M tokens |
| Cached input | $2.50 | per 1M tokens |
| Blended 3:1 | $31.22 | estimate per 1M tokens |
| 1M in + 1M out | $88.72 | estimate |
Benchmarks
Scores below are modelled estimates on a 0–100 scale. Use them to compare relative position, not as official vendor results.
| Benchmark | Score | Rank | Percentile | Relative |
|---|---|---|---|---|
| MMLU-Pro | 87.7 | 22 | 96th | |
| GPQA Diamond | 79.6 | 66 | 89th | |
| SWE-bench Verified | 74.1 | 51 | 92th | |
| HumanEval | 91.3 | 30 | 95th | |
| MATH-500 | 92.0 | 21 | 97th | |
| AIME 2025 | 80.5 | 81 | 87th | |
| LiveCodeBench | 82.7 | 18 | 97th | |
| IFEval | 90.6 | 62 | 90th | |
| TruthfulQA | 86.5 | 44 | 93th | |
| HellaSwag | 90.9 | 65 | 89th | |
| MMMU | 82.3 | 31 | 95th | |
| Arena Elo | 1456.9 | 60 | 90th |
What o3 Reasoning is good for
o3 Reasoning sits in the frontier tier of the index. It is aimed at work where answer quality matters more than unit cost: hard reasoning, multi-step coding, document analysis and multimodal inputs. At $18.07 per million input tokens and a 200,000-token context window, it is a premium option, so reserve it for tasks where a cheaper model measurably fails.
Strengths
- Top-tier average benchmark score (85.3), placing it #44 of 600.
- Large 200,000-token context window for long documents and agent traces.
- Accepts more than text, including image input where the provider supports it.
- Reasoning-oriented profile, useful for multi-step problems and structured analysis.
- Coding benchmarks are a relative strength within its tier.
Trade-offs
- Proprietary licence: you cannot download the weights or self-host the model.
- Premium input pricing at $18.07 per million tokens.
- Cost can climb quickly on long outputs and high-volume traffic.
How it compares
| Model | Provider | Context | Input / 1M | Avg score |
|---|---|---|---|---|
| Gemini 3 Pro Vision | Google DeepMind | 200000 | $17.59 | 85.5 |
| Grok 4 Pro | xAI | 1000000 | $19.00 | 85.4 |
| o4 | OpenAI | 2000000 | $17.74 | 85.4 |
| o3 Reasoning | OpenAI | 200000 | $18.07 | 85.3 |
| GPT-4.1 Pro | OpenAI | 400000 | $17.56 | 85.2 |
| Gemini 3 Flash Max | Google DeepMind | 1000000 | $17.43 | 85.0 |
FAQ
How much does o3 Reasoning cost?
o3 Reasoning is listed at $18.07 per million input tokens and $70.65 per million output tokens. Cached input is $2.50 per million tokens. A blended 3:1 input-to-output mix is about $31.22 per million tokens.
What is the context window of o3 Reasoning?
o3 Reasoning has a context window of 200,000 tokens and can emit up to 16,384 output tokens per request in this index.
Is o3 Reasoning open weights?
No. o3 Reasoning is a proprietary model with a proprietary licence, so you cannot download the weights.
How does o3 Reasoning score on benchmarks?
o3 Reasoning averages 85.3 across the scored benchmarks in this index, ranking #44 of 600 models. Its strongest relative result is LiveCodeBench at 82.7.
What is o3 Reasoning best for?
o3 Reasoning sits in the frontier tier of the index. It is aimed at work where answer quality matters more than unit cost: hard reasoning, multi-step coding, document analysis and multimodal inputs. At $18.07 per million input tokens and a 200,000-token context window, it is a premium option, so reserve it for tasks where a cheaper model measurably fails.