OpenRouter’s weekly ranking ranks second in the world. This domestic model is finally open source

Zhidongxi reported on October 15 that just now, a large model that has just ranked second in the global weekly usage list of OpenRouter Token has been open sourced! Step Star has officially opened the model weights of Step 5 Preview, and the two versions of BF16 and FP8 are simultaneously launched on HuggingFace and ModelScope. Hugging Face: https://huggingface.co/stepfun-ai/Step-5-Preview ModelScope: https://modelscope.cn/models/stepfun-ai/Step-5-Preview Step 5 Preview adopts sparse MoE architecture, with a total parameter volume of 600B, activation parameters of only 27B, and supports 1 million Token context windows. It scored 44 points in Artificial Analysis' Intelligence Index, ranking among the top three open source models in the world. After its official release, the model quickly entered the horizons of global developers. As of October 15, 2026, Step 5 Preview’s Token usage ranked second in both the weekly and daily lists of the open model platform OpenRouter, with approximately 18.8 trillion Tokens used in the past seven days. According to the Artificial Analysis evaluation data when Step 5 Preview was released, its average single-task cost is only 1/8 of that of Claude Opus 5. The total single-time cost of the former is US$0.71 (approximately RMB 4.75), while the latter is US$5.86 (approximately RMB 39.22). In terms of benchmark testing, according to the Step team, in public and internal evaluations, Step 5 Preview has demonstrated relatively balanced comprehensive capabilities in benchmark tests such as complex software engineering tasks (including long-range planning tasks), professional knowledge work, and financial fields. In Ag