o3
OpenAI · 2025
OpenAI's reasoning model with step-by-step logical inference for complex problem-solving.
Quick Facts
Parameters
Undisclosed
Context Window
128K tokens
Modalities
text
Open Source
No
Pricing
$20/mo Plus / $200/mo Pro
Released
2025
Developer
OpenAI
About
o3 is OpenAI's specialized reasoning model designed for deep, step-by-step logical inference. Unlike standard language models that generate answers directly, o3 works through problems systematically, showing its reasoning chain before arriving at conclusions. This makes it exceptionally effective for mathematical proofs, complex logic puzzles, scientific reasoning, multi-step analysis, and any task requiring careful, verifiable reasoning. o3 sets new standards on reasoning benchmarks and is available as a dedicated model in ChatGPT, complementing GPT-4o and GPT-5 for tasks requiring deliberate thought.
Strengths
- +Deep step-by-step reasoning with visible thinking chain
- +State-of-the-art on mathematical and scientific benchmarks
- +Exceptional at logic puzzles and multi-step analysis
- +Verifiable reasoning process builds trust
Weaknesses
- −Slower response due to reasoning process
- −More expensive per token than standard models
- −Text-only, no multimodal capabilities
- −Not suited for creative or casual conversation
Best For
Mathematical proofs and advanced problem-solving
Scientific research and data analysis
Complex logic and programming challenges
Any task requiring verifiable step-by-step reasoning
Pricing
Plus
$20/mo
- o3 access
- Limited reasoning messages
- Standard speed
Pro
$200/mo
- Unlimited o3
- Deep reasoning mode
- Priority access
API
TBD
- Pay-as-you-go
- Full reasoning chain
- 128K context
Benchmarks
| Benchmark | o3 | Competitor |
|---|---|---|
| AIME 2025 | 87.3% | DeepSeek-R1: 79.8% |
| GPQA Diamond | 81.2% | Claude 4 Opus: 76.8% |
Technical Specs
Parameters
Undisclosed
Context Window
128K tokens
Modalities
text
Languages
Open Source
No
Developer
OpenAI
Released: 2025
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