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AssistantStepFun

StepFun

StepFun's multimodal assistant and Step-model API platform.

Category
Assistant
Pricing
FREEMIUM
Source
Proprietary
Hosting
Cloud
Platforms
WebAPI
Models
Single model (proprietary)
Verified
Jun 10, 2026

The chat assistant and developer platform of StepFun, the Shanghai AI lab behind the Step model family. The assistant at stepfun.ai bundles web search, knowledge-base Q&A, image generation, and Step-Audio speech tools, while the open platform at platform.stepfun.ai serves Step language, audio, and image-edit models over an international API.

Capabilities 6

What it actually does — grouped by capability family.

  • Multi-model access (primary capability)
  • Transcription (STT) (secondary capability)
  • Speech synthesis (TTS) (secondary capability)
  • Voice cloning (secondary capability)
  • Text-to-image (secondary capability)
  • Image editing (secondary capability)

Pros & cons

  • Free multimodal chat
  • Step-3.5-Flash is Apache 2.0
  • Audio and image models on one API
  • Tencent-backed, well-funded
  • China-hosted data concerns
  • English UX less polished than rivals
  • Smaller ecosystem than peers

Tags

Further reading

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Open StepFun