# StepFun

> StepFun is a Shanghai-based foundation-model company founded in 2023. It develops language, vision, speech, image and video models, offers paid APIs and developer products, and works with smartphone and automotive manufacturers to bring AI agents into everyday devices.

- **Founded:** 2023
- **Headquarters:** Shanghai, China
- **Founders:** Jiang Daxin (Co-founder and CEO), Zhu Yibo (Co-founder and CTO)
- **Products:** Step 5 Preview, Step 3.7 Flash, Step 3.5 Flash, StepAudio 3, Step1X-Edit
- **Notable:** Publicly released models across text, speech, image editing and video generation., Qiming reported over 42 million smartphone installations by the end of 2025., Completed a Series B+ round exceeding RMB5 billion in January 2026.

## Products & services

- **Step 5 Preview** — Flagship agent model; 600B total and 27B active parameters, up to 1M-token context. Weights released under StepFun Model License 1.0 with additional commercial conditions.
- **Step 3.7 Flash** — Multimodal model for agent workflows, available through hosted APIs and downloadable weights.
- **Step 3.5 Flash** — Apache-2.0 model for reasoning, code and tool use; 196B total and 11B active parameters.
- **StepAudio 3** — Speech family spanning realtime conversation, recognition, synthesis, audio generation and music.
- **Step1X-Edit** — Image editing from natural-language instructions, with publicly released code and models.
- **Step-Video-T2V** — 30B-parameter text-to-video model with public inference code and weights.
- **StepFun API Platform** — Usage-priced access to language, vision and speech models through separate China and global platforms.
- **Step Code and AI Studio** — Developer coding and browser-based AI creation products listed on the company website.
- **Yuewen / Step AI** — Consumer AI assistant and creative application, historically branded Yuewen.

## Achievements

- Publicly released models across text, speech, image editing and video generation.
- Qiming reported over 42 million smartphone installations by the end of 2025.
- Completed a Series B+ round exceeding RMB5 billion in January 2026.
- Released Step 5 Preview weights in October 2026.

## Latest updates

- **2026-10** — October 15: released Step 5 Preview weights and an architecture/training blog.
- **2026-09** — StepAudio 3 Realtime technical report submitted September 12; revised October 12.
- **2026-09** — Introduced Step 5 Preview; published evaluations reference September 20.
- **2026-05** — Reports described a nearly US$2.5 billion financing and preparations for a Hong Kong listing; cited reporting did not establish completion.
- **2026-01** — Announced Yin Qi as chairman alongside the more-than-RMB5-billion B+ round.

## Links

- Website: https://www.stepfun.com/
- LinkedIn: https://www.linkedin.com/company/stepfun-ai/
- Twitter/X: https://x.com/StepFun_ai
- GitHub: https://github.com/stepfun-ai

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Profile page: https://yespress.io/stepfun
Published by YesPress — https://yespress.io
Last updated: 2026-10-25