o1-preview (09-12) vs o3
o1-preview (09-12) (2024) and o3 (2025) are frontier-tier reasoning models from OpenAI. o1-preview (09-12) ships a 128K-token context window, while o3 ships a 200K-token context window. On Google-Proof Q&A, o3 leads by 14.4 pts. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing. The goal is to make the tradeoff clear before deeper testing.
o3 is safer overall; choose o1-preview (09-12) when coding workflow support matters.
Specs
| Specification | ||
|---|---|---|
| Released | 2024-09-12 | 2025-03-31 |
| Context window | 128K | 200K |
| Parameters | — | — |
| Architecture | decoder only | decoder only |
| License | Unknown | Proprietary |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | o1-preview (09-12) | o3 |
|---|---|---|
| Input price | - | $2/1M tokens |
| Output price | - | $8/1M tokens |
| Providers | - |
Capabilities
| Capability | o1-preview (09-12) | o3 |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | Yes | Yes |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | No | Yes |
| Code execution | Yes | Yes |
Benchmarks
| Benchmark | o1-preview (09-12) | o3 |
|---|---|---|
| Google-Proof Q&A | 73.3 | 87.7 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has o1-preview (09-12) at 73.3 and o3 at 87.7, with o3 ahead by 14.4 points. The largest visible gap is 14.4 points on Google-Proof Q&A, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on structured outputs: o3. Both models share reasoning mode and code execution, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
Pricing coverage is uneven: o1-preview (09-12) has no token price sourced yet and o3 has $2/1M input tokens. Provider availability is 0 tracked routes versus 2. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose o1-preview (09-12) when coding workflow support are central to the workload. Choose o3 when coding workflow support, larger context windows, and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions.
FAQ
Which has a larger context window, o1-preview (09-12) or o3?
o3 supports 200K tokens, while o1-preview (09-12) supports 128K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Is o1-preview (09-12) or o3 open source?
o1-preview (09-12) is listed under Unknown. o3 is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for reasoning mode, o1-preview (09-12) or o3?
Both o1-preview (09-12) and o3 expose reasoning mode. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for structured outputs, o1-preview (09-12) or o3?
o3 has the clearer documented structured outputs signal in this comparison. If structured outputs is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for code execution, o1-preview (09-12) or o3?
Both o1-preview (09-12) and o3 expose code execution. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Where can I run o1-preview (09-12) and o3?
o1-preview (09-12) is available on the tracked providers still being sourced. o3 is available on OpenAI API and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-05-11. Data sourced from public model cards and provider documentation.