All Models

Step 3.5 Flash

ReasoningTool CallingAttachmentsOpen WeightsStructured Output

Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token....

Providers21
ReleasedJan 29, 2026
Input Modalitiestext, image
Output Modalitiestext
Tarsk Usecoding

Benchmarks

17
Intelligence Index

Available Providers (21)

ProviderModel IDInput CostOutput CostContextMax OutputDocs
Nvidiastepfun-ai/step-3.5-flash$0/MTok$0/MTok256K16.4K
Eden AIdeepinfra/stepfun-ai/Step-3.5-Flash$0.09/MTok$0.30/MTok262.1K256K
NanoGPTstepfun-ai/step-3.5-flash$0.10/MTok$0.30/MTok262.1K65.5K
NanoGPTstepfun-ai/step-3.5-flash-2603$0.10/MTok$0.30/MTok262.1K65.5K
SiliconFlow (China)stepfun-ai/Step-3.5-Flash$0.10/MTok$0.30/MTok262K262K
StepFun (Global)step-3.5-flash-2603$0.10/MTok$0.30/MTok256K256K
StepFun (Global)step-3.5-flash$0.10/MTok$0.30/MTok256K256K
StepFun (China)step-3.5-flash$0.10/MTok$0.30/MTok256K256K
StepFun (China)step-3.5-flash-2603$0.10/MTok$0.30/MTok256K256K
Hugging Facestepfun-ai/Step-3.5-Flash$0.10/MTok$0.30/MTok262.1K256K
EmpirioLabs AIstep-3-5-flash-2603$0.10/MTok$0.30/MTok256K131.1K
EmpirioLabs AIstep-3-5-flash$0.10/MTok$0.30/MTok256K131.1K
Kilo Gatewaystepfun/step-3.5-flash$0.10/MTok$0.30/MTok262.1K65.5K
OpenRouterstepfun/step-3.5-flash$0.10/MTok$0.30/MTok262.1K65.5K
SiliconFlowstepfun-ai/Step-3.5-Flash$0.10/MTok$0.30/MTok262K262K
ZenMuxstepfun/step-3.5-flash$0.10/MTok$0.30/MTok256K64K
Qiniustepfun/step-3.5-flash—/MTok—/MTok64K4.1K
StepFun Step Plan (China)step-3.5-flash—/MTok—/MTok256K256K
StepFun Step Plan (China)step-3.5-flash-2603—/MTok—/MTok256K256K
StepFun Step Plan (Global)step-3.5-flash—/MTok—/MTok256K256K
StepFun Step Plan (Global)step-3.5-flash-2603—/MTok—/MTok256K256K

Capabilities

Reasoning
Tool Calling
Attachments
Open Weights
Structured Output