Reportedly: StepFun Step 5 Preview model goes live on Tencent WorkBuddy with exclusive free access from October 12 to 25
Reported by IT Home · not yet confirmed by the company or a second independent outlet. We update this page when it is.
StepFun announced that its Step 5 Preview model is now available on Tencent WorkBuddy, with exclusive free access from October 12 to 25, 2026, IT Home reported. The model uses a sparse MoE architecture with 600B total parameters, 27B active parameters, and a 1 million token context window.
China context
- Original name
- 阶跃星辰
- Outside China
- Not stated in the sources yet
- Claims
- Company-reported; not yet independently evaluated
- For builders
- Developers outside China should monitor the October 15 open-source release to assess whether the model weights are accessible and usable under a permissive license.
- For investors
- The free access period and open-source commitment may accelerate adoption of StepFun's models, but investors should verify actual usage metrics and enterprise uptake after the promotional window.
Translated from Chinese. Quotes and facts link to the original sources.
StepFun has launched its Step 5 Preview model on Tencent WorkBuddy, offering exclusive free access from October 12 to 25, 2026. The model, first introduced on September 20, 2026, targets AI programming, software engineering, professional knowledge work, and finance, and is scheduled to open-source full weights on October 15, 2026. It features a sparse Mixture-of-Experts architecture with 600 billion total parameters, 27 billion active parameters, and a 1 million token context window, natively supporting text and visual inputs.
The Step 5 Preview model employs a sparse Mixture-of-Experts (MoE) architecture with 600B total parameters and 27B active parameters, enabling efficient inference for large-scale tasks. It supports a 1 million token context window and native multimodal input (text and vision), positioning it for complex agentic workflows in coding and professional domains.
Tencent WorkBuddy users gain free access to a 600B-parameter model for two weeks, potentially lowering the cost of testing advanced AI capabilities in enterprise workflows. Competitors offering similar coding and agentic models may face pressure to match this promotional pricing or risk losing developer mindshare.
The exclusive free access period on Tencent WorkBuddy provides a low-risk opportunity for enterprises to evaluate Step 5 Preview's capabilities in real-world tasks without upfront cost. The upcoming open-source release may further reduce adoption barriers and enable customization.
The full open-source release of Step 5 Preview weights on October 15, 2026, will be a key signal to watch. If the weights are released as announced, developers outside China can independently verify the model's performance and potentially deploy it, shifting the competitive landscape for open-weights models.