StepFun

Shanghai Jieyue Xingchen Intelligent Technology Co., Ltd
StepFun
Native name
上海阶跃星辰智能科技有限公司
TypePrivate
IndustryInformation technology
Founded6 April 2023; 3 years ago (2023-04-06)
Founders
  • Jiang Daxin
  • Zhu Yibo
  • Jiao Binxing
HeadquartersShanghai, China
Area served
Worldwide
Websitewww.stepfun.com Edit this on Wikidata

Shanghai Jieyue Xingchen Intelligent Technology Co., Ltd, known as StepFun, is an artificial intelligence (AI) company based in Shanghai, China. It has been dubbed one of China's 6 "AI Tiger" companies by investors.

Background

StepFun was founded in April 2023 by former Microsoft employees. Investors include Tencent, Qiming Venture Partners and Shanghai State-owned Capital Investment.

In July 2025 at the World Artificial Intelligence Conference, StepFun announced the "Model-Chip Ecosystem Innovation Alliance" which consisted of Chinese developers of large language models (LLMs) and AI chip manufacturers. This included companies such as Huawei, Biren Technology, Moore Threads and Enflame. Another second alliance named the "Shanghai General Chamber of Commerce AI Committee" was also established that included StepFun, SenseTime, MiniMax, MetaX and Iluvatar CoreX.

On 25 February 2026, it was reported that StepFun was seeking an initial public offering on the Hong Kong Stock Exchange.

StepFun focuses on multimodal models which are designed to understand multiple types of input data such as text, video and audio.

Products

In July 2024 at the World Artificial Intelligence Conference, StepFun officially launched Step-2, a trillion-parameter LLM, along with the Step-1.5V multimodal model and the Step-1X image generation model.

In February 2025, StepFun and Geely jointly announced the open-sourcing of two multimodal large models to global developers. They were Step-Video-T2V and Step-Audio.

In July 2025, StepFun released Step 3. The Model-Chip Ecosystem Innovation Alliance aimed to optimize Step 3 for domestic chips.

In April 2025, Step-R1-V-Mini was released. It is a multimodal reasoning model designed for visual interpretation and image understanding.

In February 2026, Step 3.5 Flash, a mixture-of-experts model with 196 billion parameters and 11 billion active parameters was released under the free and open-source Apache 2.0 license. It supports tool use and a 256k token context window.

On 13 October 2026, StepFun launched the STEPX Neo, a smartphone priced at CN¥3,999 running Step AOS, an operating system the company said was rebuilt around an on-device AI agent, Amoo, rather than adding AI as a separate app. The launch price was described as a "full-stack" bundle covering the hardware, software and a year of access to StepFun's AI token plan.

Models

List of StepFun models
Name Release date License Ref.
Step 3.5 Flash February 2026 Apache 2.0
Step 3.7 Flash May 2026 Apache 2.0
Step 5 Preview September 18, 2026 Closed weights

See also

References

  1. ↑ "Meet the 'Six Tigers' that dominate China's AI industry". Quartz. 10 March 2025. Retrieved 13 September 2025.
  2. ↑ Chen, Wency (21 June 2024). "Shanghai AI start-up bets on 'scaling law' to overcome US chip ban". South China Morning Post. Retrieved 1 January 2026.
  3. ↑ Jiang, Ben (26 December 2024). "Shanghai firm helps AI start-up Stepfun raise 'hundreds of millions of dollars'". South China Morning Post. Retrieved 1 January 2026.
  4. 1 2 Mo, Liam (29 July 2025). "Chinese AI firms form alliances to build domestic ecosystem amid US curbs". Reuters.
  5. ↑ Fioretti, Julia (25 February 2026). "Tencent-Backed AI Startup StepFun Is Said to Plan Hong Kong IPO". Bloomberg News.
  6. 1 2 Jiang, Ben (12 May 2025). "China's StepFun aims to stand out in AI race with multimodal models". South China Morning Post. Retrieved 1 January 2026.
  7. ↑ Chen, Wency (8 July 2024). "Chinese AI can benefit from bigger models, more data, says start-up founder". South China Morning Post. Retrieved 1 January 2026.
  8. ↑ Xiao, Yisi (18 February 2025). "China's Geely and Stepfun Join Open-Source AI Trend With Two Models". Yicai Global. Retrieved 1 January 2026.
  9. ↑ Berman, Noah (8 June 2025). "What is StepFun?". The Wire China. Retrieved 1 January 2026.
  10. ↑ Zhang, Yushuo (29 July 2025). "USD2.3 Billion of Deals Are Inked at WAIC 2025 in Shanghai". Yicai Global. Retrieved 1 January 2026.
  11. ↑ "Chinese AI chipmakers join forces with StepFun to counter Nvidia's return to China". TechNode. 29 July 2025. Retrieved 1 January 2026.
  12. 1 2 Jiang, Ben (3 February 2026). "Compact AI model from China's StepFun outshines rivals from DeepSeek, Moonshot". South China Morning Post. Archived from the original on 4 February 2026. Retrieved 14 April 2026.
  13. ↑ "Step 3.5 Flash: Fast Enough to Think. Reliable Enough to Act". static.stepfun.com. Retrieved 2 February 2026.
  14. ↑ "Chinese AI Startup StepFun Launches Smartphone to Challenge Tech Giants". Caixin Global. 14 October 2026. Retrieved 16 October 2026.
  15. ↑ "stepfun-ai/Step-3.5-Flash". 14 March 2026. Retrieved 14 April 2026 – via Hugging Face.
  16. ↑ "stepfun-ai/Step-3.7-Flash". 29 May 2026. Retrieved 2 June 2026 – via Hugging Face.
  17. ↑ "Step 5 Preview". Epoch AI. Retrieved 5 October 2026.
  18. ↑ "Introducing Step 5 Preview: Advancing the Pareto Frontier". LinkedIn. Retrieved 5 October 2026.