Step-2-16k-exp-202412 is an experimental large language model developed by the Chinese AI startup StepFun (阶跃星辰). It is a variant of the Step-2 series, which utilizes a Mixture-of-Experts (MoE) architecture to achieve a scale exceeding one trillion parameters. This specific iteration is configured with a 16,000-token context window, balancing high-capacity reasoning with computational efficiency.
The model is recognized for its performance in logical reasoning and instruction following, frequently appearing as a high-ranking entry on global benchmarks such as Livebench and the LMSYS Chatbot Arena. As an experimental release, it serves as a snapshot of StepFun's ongoing research and development, incorporating refined training data and architectural optimizations that differentiate it from the standard Step-2 production models.
Primarily intended for evaluation and testing, the model is available through the creator's API platform. It provides developers with access to the latest capabilities in the StepFun ecosystem, particularly in areas involving complex problem-solving and Chinese-English bilingual understanding.