Step 3.5 Flash 2603Open weights
StepFun · released 2026-04-02
The official API price of Step 3.5 Flash 2603 is $0.10461 per 1M input tokens and $0.31384 per 1M output tokens (as of 2026-11-12). Context window: 256K tokens, up to 256K output tokens per request. 6 providers sell it. The lowest is EmpirioLabs AI: $0.1 input, $0.3 output.
Price by providerUSD per 1M tokens
| Provider | Input | Output | Cached | Notes | |
|---|---|---|---|---|---|
| StepFun (China)Officialstep-3.5-flash-2603 | $0.10461 | $0.31384 | $0.02092 | Official | Official docs |
 EmpirioLabs AILoweststep-3-5-flash-2603 | $0.1 | $0.3 | $0.02 | Lowest | Official docs |
NNanoGPTstepfun-ai/ | $0.1 | $0.3 | $0.05 | Official docs | |
SStepFun (Global)step-3.5-flash-2603 | $0.1 | $0.3 | $0.02 | Official docs | |
SStepFun Step Plan (Global)step-3.5-flash-2603 | — | — | — | Official docs | |
SStepFun Step Plan (China)step-3.5-flash-2603 | — | — | — | Official docs |
Providers are those listed by models.dev. This site has not vetted them one by one; each provider's own page has the binding price.
About
StepFun flash model for efficient multimodal reasoning, coding, and tool use
Description from models.dev.
Specs
- Type
- Text
- Context
- 256K
- Max output
- 256K
- Input
- Text
- Output
- Text
- Reasoning
- Yes
- Tool calling
- Yes
- Structured output
- Yes
- Knowledge cutoff
- 2025-01
- Open weights
- Yes
- Released
- 2026-04-02
Source
Prices and specs come from models.dev (MIT licence), updated 2026-11-12. Each provider's name links to its official docs. A provider priced at 0 usually includes the model in a subscription; it is not necessarily a free API.