# StepFun > A Shanghai lab shipping efficient multimodal models, many under Apache 2.0. Canonical: https://www.subconscious.dev/providers/stepfun · By The Subconscious Team · Updated September 30, 2026 - Founded: 2023 - Example models: Step 3.7 Flash, Step3 - Website: https://www.stepfun.com ## Overview StepFun is a Shanghai AI lab known for efficient multimodal models, with a mix of proprietary API models and open-weight releases. Its current workhorse, Step 3.7 Flash, came out in May 2026 as a 198B mixture-of-experts vision-language model with only 11B active parameters. It has 256K context, selectable reasoning levels, tool use and structured outputs, and it ships under Apache 2.0. StepFun's own API prices it at $0.20 in and $1.15 out per million tokens, and OpenRouter carries it too. StepFun's research leans on model and system co-design to cut decoding cost. The earlier Step3, a 321B multimodal reasoning model with 38B active, used Multi-Matrix Factorization Attention and Attention-FFN Disaggregation to stay cheap on both flagship and low-end accelerators. The lab also builds speech and audio models, and its Step-2 line reached the trillion-parameter range. The platform exposes an OpenAI-compatible API, and the open weights run on vLLM and SGLang. ## Upsides - Low-cost multimodal models that read images and video with long context. - Permissive Apache 2.0 weights on key releases, which helps self-hosting. ## Core use cases - Vision and video understanding inside cost-sensitive agents. - Teams that want a small-active-parameter model to self-host cheaply. ## Downsides - Trails frontier models on hard multimodal reasoning benchmarks. - Thin Western distribution and support, with China-hosted first-party inference. ## At a glance | Attribute | Value | |---|---| | Model access | Open (Apache 2.0) and API models | | Flagship models | Step 3.7 Flash, Step3 | | Speed | ~128 tok/s on Step 3.7 Flash | | Price | $0.20 in, $1.15 out (Step 3.7 Flash) | | Customization | Open weights to fine-tune | | Deployment | First-party API, OpenRouter | | Long context | 256K | ## FAQ ### What is StepFun? StepFun is a Shanghai AI lab known for efficient multimodal models, with a mix of proprietary API models and open-weight releases. Its current workhorse, Step 3.7 Flash, came out in May 2026 as a 198B mixture-of-experts vision-language model with only 11B active parameters. It has 256K context, selectable reasoning levels, tool use and structured outputs, and it ships under Apache 2.0. StepFun's own API prices it at $0.20 in and $1.15 out per million tokens, and OpenRouter carries it too. ### What is StepFun best for? Vision and video understanding inside cost-sensitive agents; Teams that want a small-active-parameter model to self-host cheaply. ### How much does StepFun cost? StepFun pricing at a glance: $0.20 in, $1.15 out (Step 3.7 Flash). Rates change often, so check StepFun's pricing page before committing. ### How much context does StepFun support? StepFun's long-context support: 256K. ### What are the downsides of StepFun? Trails frontier models on hard multimodal reasoning benchmarks; Thin Western distribution and support, with China-hosted first-party inference. ### What are the best alternatives to StepFun? Common alternatives include Subconscious, OpenAI, Anthropic, Google Vertex AI, Amazon Bedrock. Each has a head-to-head comparison with StepFun on this site. ## Comparisons - [Subconscious vs StepFun](https://www.subconscious.dev/compare/subconscious-vs-stepfun.md) - [OpenAI vs StepFun](https://www.subconscious.dev/compare/openai-vs-stepfun.md) - [Anthropic vs StepFun](https://www.subconscious.dev/compare/anthropic-vs-stepfun.md) - [Google Vertex AI vs StepFun](https://www.subconscious.dev/compare/google-vertex-vs-stepfun.md) - [Amazon Bedrock vs StepFun](https://www.subconscious.dev/compare/aws-bedrock-vs-stepfun.md) - [Together AI vs StepFun](https://www.subconscious.dev/compare/together-ai-vs-stepfun.md) - [Fireworks AI vs StepFun](https://www.subconscious.dev/compare/fireworks-vs-stepfun.md) - [Baseten vs StepFun](https://www.subconscious.dev/compare/baseten-vs-stepfun.md) - [Groq vs StepFun](https://www.subconscious.dev/compare/groq-vs-stepfun.md) - [Cerebras vs StepFun](https://www.subconscious.dev/compare/cerebras-vs-stepfun.md) - [DeepInfra vs StepFun](https://www.subconscious.dev/compare/deepinfra-vs-stepfun.md) - [Modal vs StepFun](https://www.subconscious.dev/compare/modal-vs-stepfun.md) - [xAI vs StepFun](https://www.subconscious.dev/compare/xai-vs-stepfun.md) - [DeepSeek vs StepFun](https://www.subconscious.dev/compare/deepseek-vs-stepfun.md) - [Moonshot AI vs StepFun](https://www.subconscious.dev/compare/moonshot-ai-vs-stepfun.md) - [Z.ai vs StepFun](https://www.subconscious.dev/compare/z-ai-vs-stepfun.md) - [Alibaba Cloud vs StepFun](https://www.subconscious.dev/compare/alibaba-cloud-vs-stepfun.md) - [Meta vs StepFun](https://www.subconscious.dev/compare/meta-vs-stepfun.md) - [SambaNova vs StepFun](https://www.subconscious.dev/compare/sambanova-vs-stepfun.md) - [Nebius vs StepFun](https://www.subconscious.dev/compare/nebius-vs-stepfun.md) - [fal vs StepFun](https://www.subconscious.dev/compare/fal-vs-stepfun.md) - [Novita AI vs StepFun](https://www.subconscious.dev/compare/novita-ai-vs-stepfun.md) - [Parasail vs StepFun](https://www.subconscious.dev/compare/parasail-vs-stepfun.md) - [Inference.net vs StepFun](https://www.subconscious.dev/compare/inference-net-vs-stepfun.md) - [GMI Cloud vs StepFun](https://www.subconscious.dev/compare/gmi-cloud-vs-stepfun.md) - [Sail Research vs StepFun](https://www.subconscious.dev/compare/sail-research-vs-stepfun.md) - [Morph vs StepFun](https://www.subconscious.dev/compare/morph-vs-stepfun.md) - [Relace vs StepFun](https://www.subconscious.dev/compare/relace-vs-stepfun.md) - [TypeSafe AI vs StepFun](https://www.subconscious.dev/compare/typesafe-ai-vs-stepfun.md) - [StepFun vs Runware](https://www.subconscious.dev/compare/stepfun-vs-runware.md) - [StepFun vs StreamLake](https://www.subconscious.dev/compare/stepfun-vs-streamlake.md) - [StepFun vs Wafer](https://www.subconscious.dev/compare/stepfun-vs-wafer.md) - [StepFun vs RunInfra](https://www.subconscious.dev/compare/stepfun-vs-runinfra.md) - [StepFun vs Particle.AI](https://www.subconscious.dev/compare/stepfun-vs-particle-ai.md) ## Sources - [Step model family, LLM Reference](https://www.llmreference.com/model-family/step) - [Step3 on Hugging Face](https://huggingface.co/stepfun-ai/step3) Pricing and model lineups change often; figures are a snapshot.