o1-pro

o1-pro is OpenAI's reasoning model trained with reinforcement learning to perform extended chain-of-thought processing on complex problems, with a 200k token context window.

Strengths

Excels at deep reasoning over long contexts, breaking down intricate multi-step problems through extended chain-of-thought processing.

Best for

Research, mathematical problem-solving, code generation, and tasks requiring sustained reasoning across large documents or codebases.

Limitations

Slower than standard models due to reasoning overhead, and has been superseded by o3 which received an 80% price cut in June 2025.