OpenAI o1 is the most powerful language model available in ChatGPT as of 2025, designed to solve the most complex and high-stakes problems in research, engineering, and beyond. Optimized for depth, accuracy, and reliability, o1 represents a new tier of research-grade intelligence — with o1 pro mode pushing the boundaries even further through higher compute and more deliberative reasoning.

Core Strengths

• Research-grade intelligence with cutting-edge performance
• Built for high-stakes tasks in law, medicine, data science, and engineering
• o1 pro mode enables deeper, more reliable thinking with extra compute
• Powers ChatGPT’s Pro experience for professionals and researchers
• Outperforms previous models (GPT-4o, GPT-4-turbo) on hard problems
• Evaluated using stricter reliability metrics (4/4 accuracy)

Model Performance

Competition Math (AIME 2024):         
- o1-preview:     50  
- o1:             78  
- o1 pro mode:    86  

Competition Code (Codeforces):        
- o1-preview:     62  
- o1:             89  
- o1 pro mode:    90  

PhD-Level Science (GPQA Diamond):     
- o1-preview:     74  
- o1:             76  
- o1 pro mode:    79  

Competition Math (AIME 2024):         
- o1-preview:     37  
- o1:             67  
- o1 pro mode:    80  

Competition Code (Codeforces):        
- o1-preview:     26  
- o1:             64  
- o1 pro mode:    75  

PhD-Level Science (GPQA Diamond):     
- o1-preview:     58  
- o1:             67  
- o1 pro mode:    74  

Use Cases

• Research-grade analysis in data science, law, and medicine
• Debugging and deep investigation in advanced software engineering
• Complex reasoning in math, science, and multimodal tasks
• Writing and validating technical content with 4/4 reliability
• High-compute applications that benefit from extra deliberation time