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StepFun

Step 3.5 Flash

StepFun flash lane for quick multimodal reasoning and coding assistance

Model facts

Context window
256K tokens
Maximum output
256K tokens
Cheapest paid input
$0.09 per 1M tokens
Cheapest paid output
$0.3 per 1M tokens
Open weights
yes
Providers
14

Capabilities and modalities

reasoning, tool calling, structured output, attachments, temperature control, open weights, text, image.

Artificial Analysis benchmarks

Compare this model on the full LLM benchmark leaderboard.

ConfigurationAAICodingMathOutput tokens/s
default26.0not measurednot measurednot measured

Observed price history

  • 2026-08-24: $0.09 input / $0.3 output per 1M tokens

API providers

  • Nvidia — model id stepfun-ai/step-3.5-flash; free input / free output per 1M tokens; provider documentation
  • Eden AI — model id deepinfra/stepfun-ai/Step-3.5-Flash; $0.09 input / $0.3 output per 1M tokens; provider documentation
  • OpenRouter — model id stepfun/step-3.5-flash; $0.1 input / $0.3 output per 1M tokens; provider documentation
  • EmpirioLabs AI — model id step-3-5-flash; $0.1 input / $0.3 output per 1M tokens; provider documentation
  • Hugging Face — model id stepfun-ai/Step-3.5-Flash; $0.1 input / $0.3 output per 1M tokens; provider documentation
  • Kilo Gateway — model id stepfun/step-3.5-flash; $0.1 input / $0.3 output per 1M tokens; provider documentation
  • NanoGPT — model id stepfun-ai/step-3.5-flash; $0.1 input / $0.3 output per 1M tokens; provider documentation
  • StepFun (China) — model id step-3.5-flash; $0.1 input / $0.3 output per 1M tokens; provider documentation
  • StepFun (Global) — model id step-3.5-flash; $0.1 input / $0.3 output per 1M tokens; provider documentation
  • ZenMux — model id stepfun/step-3.5-flash; $0.1 input / $0.3 output per 1M tokens; provider documentation
  • Arena — model id step-3.5-flash; not published input / not published output per 1M tokens; provider documentation
  • Qiniu — model id stepfun/step-3.5-flash; not published input / not published output per 1M tokens; provider documentation
  • StepFun Step Plan (China) — model id step-3.5-flash; not published input / not published output per 1M tokens; provider documentation
  • StepFun Step Plan (Global) — model id step-3.5-flash; not published input / not published output per 1M tokens; provider documentation