Two leading Chinese AI labs, DeepSeek and Stepfun, are pursuing fundamentally different strategies in 2026. DeepSeek, based in Hangzhou, is doubling down on reasoning and price, offering open-weight models with transparent chain-of-thought and the lowest API pricing among frontier LLMs. Stepfun, headquartered in Shanghai, is going all-in on multimodal generation, with a flagship model (Step-3.5 Flash) that excels in video, audio, and document understanding.
DeepSeek's strengths lie in its best-in-class reasoning models (R1, V4) and coding performance. It leads open benchmarks on SWE-Bench, HumanEval, and LiveCodeBench, making it the go-to choice for coding agents and dev tools. Its API is 5–10× cheaper than Stepfun's Step-2 per million tokens, and it releases full flagship weights under MIT license for self-hosting.
Stepfun's advantages are in multimodal capabilities. Its Step-Video-T2V is an open-source 30B-parameter text-to-video model producing 540p clips, while Step-Audio-Chat handles end-to-end speech with sub-second latency. Step-3.5 Flash and Step-2 offer up to 256K token context windows and native document image processing, outperforming DeepSeek in long-document analysis and multimodal tasks.
Which one should you pick? For SaaS chatbots needing cheap reliable APIs, DeepSeek V4 is the clear winner. For building TikTok-style apps with text-to-video or real-time voice assistants, Stepfun is unmatched. Developers needing open weights for on-prem deployment will prefer DeepSeek, while those requiring large context windows or multimodal document handling should lean toward Stepfun.
Both labs update their pricing and tiers frequently. As of May 2026, DeepSeek offers free chat on chat.deepseek.com and free local deployment, while Stepfun provides limited free quota on its Yuewen consumer app and charges per call for video and audio APIs.