Step-3.5-Flash
Model Information
| Slug | step-3-5-flash |
|---|---|
| LLM.txt | View |
| Release Date | February 2, 2026 |
| AIME 2025 | 0.973 |
| SWE Bench | 0.744 |
| Browse Comp | 0.69 |
Organization
| Name | StepFun |
|---|---|
| Website | https://platform.stepfun.ai |
Model Description
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. It is a reasoning model that is incredibly speed efficient even at long contexts.
Available at 27 Providers
| Provider | Type | Model Name | Original Model | Input ($/1M) | Output ($/1M) | Free | Actions | |
|---|---|---|---|---|---|---|---|---|
|
Nvidia |
step-3.5-flash
|
stepfun-ai/step-3.5-flash
|
$0.00 | $0.00 | |||
|
ZenMUX |
StepFun: Step 3.5 Flash (Free)
|
stepfun/step-3.5-flash-free
|
$0.00 | $0.00 | |||
|
AIHubMix |
step-3.5-flash-free
|
step-3.5-flash-free
|
$0.00 | $0.00 | |||
|
Kilo Code |
Code
|
StepFun: Step 3.5 Flash (free)
|
stepfun/step-3.5-flash:free
|
$0.00 | $0.00 | ||
|
OpenRouter |
Chat
Code
|
Step 3.5 Flash (free)
|
stepfun/step-3.5-flash:free
|
$0.00 | $0.00 | ||
|
Routeway |
StepFun: Step 3.5 Flash (Free)
|
step-3.5-flash:free
|
$0.00 | $0.00 | |||
|
|
OpenRouter |
Chat
Code
|
Step 3.5 Flash
|
stepfun/step-3.5-flash
|
$0.10 | $0.30 | ||
|
|
ZenMUX |
StepFun: Step 3.5 Flash
|
stepfun/step-3.5-flash
|
$0.10 | $0.30 | |||
|
|
AIHubMix |
step-3.5-flash
|
step-3.5-flash
|
$0.10 | $0.30 | |||
|
|
Kilo Code |
Code
|
StepFun: Step 3.5 Flash
|
stepfun/step-3.5-flash
|
$0.10 | $0.30 | ||
|
SiliconFlow |
Step-3.5-Flash
|
stepfun-ai/Step-3.5-Flash
|
$0.10 | $0.30 | |||
|
Chats-LLM |
Chat
|
StepFun: Step 3.5 Flash
|
step-3.5-flash
|
$0.10 | $0.30 | ||
|
SiliconFlow (China) |
stepfun-ai/Step-3.5-Flash
|
stepfun-ai/Step-3.5-Flash
|
$0.10 | $0.30 | |||
|
WaveSpeed AI |
Chat
Code
|
step-3.5-flash
|
stepfun/step-3.5-flash
|
$0.10 | $0.30 | ||
|
|
Routeway |
StepFun: Step 3.5 Flash
|
step-3.5-flash
|
$0.10 | $0.30 | |||
|
302.AI |
step-3.5-flash
|
step-3.5-flash
|
$0.11 | $0.33 | |||
|
Nano-GPT |
Step 3.5 Flash
|
stepfun-ai/step-3.5-flash
|
- | - | |||
|
StepFun |
step-3.5-flash
|
- | - | ||||
|
Arena AI |
Chat
|
step-3.5-flash
|
- | - | |||
|
Yupp |
Chat
|
Step 3.5 Flash (OpenRouter)
|
stepfun/step-3.5-flash
|
- | - | ||
|
LangDB |
step-3.5-flash
|
step-3.5-flash
|
- | - | |||
|
ApiYI |
Chat
Code
|
step-3.5-flash
|
step-3.5-flash
|
- | - | ||
|
Airforce API |
step-3.5-flash
|
step-3.5-flash:free
|
- | - | |||
|
Writingmate |
Chat
Code
|
StepFun: Step 3.5 Flash
|
stepfun/step-3.5-flash
|
- | - | ||
|
ValorGPT |
ST
|
stepfun-step-3.5-flash
|
- | - | |||
|
|
ValorGPT |
ST
|
stepfun-step-3.5-flash-free
|
- | - | |||
|
Qiniu |
Stepfun/Step-3.5 Flash
|
stepfun/step-3.5-flash
|
- | - |