o1 Models by OpenAI
Last refreshed 2026-05-19. Next refresh: weekly.
Details
Capabilities
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WebsiteAbout
OpenAI's o1 family of large language models (LLMs) represents a significant advancement in AI's reasoning capabilities 4712. Unlike previous models that primarily focused on predicting the next word in a sequence, o1 models are trained to "think" before responding, employing a chain-of-thought process to solve complex problems 4712. This involves breaking down complex tasks into smaller, manageable steps, exploring different approaches, and correcting errors along the way 4712. The o1 models demonstrate improved performance on various benchmarks, including those involving mathematics, coding, and science, rivaling or exceeding the capabilities of human experts in certain areas 4712. However, these models are still under development and may lack some features found in earlier models, such as web browsing and image processing 15.
Decision facts
- Best fit
- reasoningstructured outputscode execution
- Capability starting point
- o1-preview (09-12) with 128k context and reasoning
- Lowest tracked input
- o1-mini (09-12) · $1.1/1M · Replicate API
- Closest related family
- GPT Realtime 2
Current Variants
Use-when guidance is based on each model's tracked capabilities, context window, release date, and replacement status.
Use when the workload needs 200k context and structured outputs.
Use when the workload needs 128k context, reasoning, and code execution.
Use when the workload needs 128k context, reasoning, and code execution.
| Model | Use when | Released | Signals | Status |
|---|---|---|---|---|
| o1-pro | Use when the workload needs 200k context and structured outputs. | 2024-12 | 200k contextstructured outputs | Current |
| o1-preview (09-12) | Use when the workload needs 128k context, reasoning, and code execution. | 2024-09 | 128k contextreasoningcode execution | Current |
| o1-mini (09-12) | Use when the workload needs 128k context, reasoning, and code execution. | 2024-09 | 128k contextreasoningcode execution | Current |
Release Timeline
2 release groupsReplaced By
Keep for legacy integrations; evaluate o3 before new work.
Specifications(4 models)
| Model | Released | Context | Reasoning | Structured Outputs | Code Exec |
|---|---|---|---|---|---|
| o1-pro | 2024-12 | 200k | No | Yes | No |
| o1-preview (09-12) | 2024-09 | 128k | Yes | No | Yes |
| o1-mini (09-12) | 2024-09 | 128k | Yes | No | Yes |
Available From(3 providers)
Pricing
| Model | Provider | Input / 1M | Output / 1M | Type |
|---|---|---|---|---|
| o1-mini (09-12) | Replicate API | $1.1 | $4.4 | Serverless |
| o1-pro | OpenRouter | $150 | $600 | Serverless |
Popular comparisons in this family
Comparisons
- o1 (12-17) vs Claude 3.7 Sonnet
- o1 (12-17) vs DeepSeek R1
- GPT-4o (08-06) vs o1 (12-17)
- o3 vs o1 (12-17)
