OpenAI · capability answer
What does GPT-5.5 Mini do?
Fast, cheap frontier-adjacent workhorse.
The short answer
GPT-5.5 Mini is built by OpenAI and is positioned for code, chat and summarization. Our readings score it strongest on response speed and multi-step reasoning.
Its weakest measured axis is data analysis (84/100), so plan around that when the work depends on it. Access is freemium, and the weights are closed, so you can only reach it through the vendor's own service.
Reasoning
88
Coding
87
Writing
85
Analysis
84
Speed
93
Energy, carbon and water
Carbon footprint reads 68/100. The energy mix is mixed, and disclosure covers some but not all serving regions.
Water and local impact reads 60/100. Some sites use evaporative cooling in regions with moderate water stress.
Speed and efficiency also matter here: a 93/100 speed reading means fewer compute-seconds per answer for routine work.