gpt-5.1-thinking-plus

GPT-5.1-thinking-Plus is an iterative version based on GPT-5, featuring "deep reasoning + multi-step logical planning." It automatically adjusts the thinking duration based on the task: simpler tasks are handled faster, while more complex ones extend the reasoning chain to deliver more reliable answers. This version is particularly well-suited for applications requiring advanced reasoning abilities, such as complex analysis, long-document writing, research reports, code design, and planning-oriented tasks. Functionally, it maintains a natural conversational experience, but its core strength lies in "enhanced logic and more sustained thinking."