StepFun
Step 3.5 Flash 2603
StepFun flash model for efficient multimodal reasoning, coding, and tool use
Model facts
- Context window
- 256K tokens
- Maximum output
- 256K tokens
- Cheapest paid input
- $0.1 per 1M tokens
- Cheapest paid output
- $0.3 per 1M tokens
- Open weights
- yes
- Providers
- 6
Capabilities and modalities
reasoning, tool calling, structured output, temperature control, open weights, text.
Artificial Analysis benchmarks
Compare this model on the full LLM benchmark leaderboard.
| Configuration | AAI | Coding | Math | Output tokens/s |
|---|---|---|---|---|
| default | 26.5 | not measured | not measured | not measured |
Observed price history
- 2026-08-24: $0.1 input / $0.3 output per 1M tokens
API providers
- EmpirioLabs AI — model id step-3-5-flash-2603; $0.1 input / $0.3 output per 1M tokens; provider documentation
- NanoGPT — model id stepfun-ai/step-3.5-flash-2603; $0.1 input / $0.3 output per 1M tokens; provider documentation
- StepFun (China) — model id step-3.5-flash-2603; $0.1 input / $0.3 output per 1M tokens; provider documentation
- StepFun (Global) — model id step-3.5-flash-2603; $0.1 input / $0.3 output per 1M tokens; provider documentation
- StepFun Step Plan (China) — model id step-3.5-flash-2603; not published input / not published output per 1M tokens; provider documentation
- StepFun Step Plan (Global) — model id step-3.5-flash-2603; not published input / not published output per 1M tokens; provider documentation