A compact yet powerful reasoning MoE model from OpenAI, featuring 20.9 billion total parameters (with 3.61 billion activated per token), capable of running on just 16GB of memory—making it ideal for local deployment using widely accessible consumer hardware. Despite its efficiency, it retains all advanced reasoning and tool-use capabilities, outperforming not only existing open-source models but also OpenAI's popular o3-mini on a range of key benchmarks. This makes gpt-oss-20b a strong choice for diverse research and product applications.