# Step-3.5-Flash

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.

## Model Information

- **Organization**: [StepFun](/llm.txt)
- **Slug**: step-3-5-flash
- **Available at Providers**: 22
- **Release Date**: February 2, 2026

### Benchmark Scores
- Weekly: 1.94
- AIME 2025: 0.973
- SWE Bench: 0.744
- Browsecomp: 0.69

## Providers

| Provider | Name | $ Input (per 1M) | $ Output (per 1M) | Free | Link |
|----------|------|-----------------|------------------|------|------|
| [Nvidia](/llm/nvidia.txt) | step-3.5-flash |  |  |  | [View](https://build.nvidia.com/stepfun-ai/step-3.5-flash) |
| [OpenRouter](/llm/openrouter.txt) | Step 3.5 Flash | 0.10 | 0.30 |  | [View](https://openrouter.ai/stepfun/step-3.5-flash) |
| [ZenMUX](/llm/zenmux.txt) | StepFun: Step 3.5 Flash | 0.10 | 0.30 |  |  |
| [ZenMUX](/llm/zenmux.txt) | StepFun: Step 3.5 Flash (Free) | 0.00 | 0.00 | Yes |  |
| [Nano-GPT](/llm/nanogpt.txt) | Step 3.5 Flash |  |  |  |  |
| [302.AI](/llm/302ai.txt) | step-3.5-flash | 0.11 | 0.33 |  | [View](https://302ai-en.apifox.cn/api-207705112) |
| [AIHubMix](/llm/aihubmix.txt) | step-3.5-flash-free | 0.00 | 0.00 | Yes | [View](https://aihubmix.com/model/step-3.5-flash-free) |
| [AIHubMix](/llm/aihubmix.txt) | step-3.5-flash | 0.10 | 0.30 |  | [View](https://aihubmix.com/model/step-3.5-flash) |
| [StepFun](/llm/stepfun.txt) |  |  |  |  | [View](https://platform.stepfun.ai) |
| [Arena AI](/llm/arenaai.txt) |  |  |  |  |  |
| [Kilo Code](/llm/kilocode.txt) | StepFun: Step 3.5 Flash (free) | 0.00 | 0.00 | Yes |  |
| [Kilo Code](/llm/kilocode.txt) | StepFun: Step 3.5 Flash | 0.10 | 0.30 |  | [View](https://kilo.ai/models/stepfun/step-3.5-flash) |
| [SiliconFlow](/llm/siliconflow.txt) | Step-3.5-Flash | 0.10 | 0.30 |  | [View](https://www.siliconflow.com./models/step-3-5-flash) |
| [Yupp](/llm/yupp.txt) | Step 3.5 Flash (OpenRouter) |  |  |  |  |
| [Chats-LLM](/llm/chatsllm.txt) | StepFun: Step 3.5 Flash | 0.10 | 0.30 |  |  |
| [SiliconFlow (China)](/llm/siliconflowcn.txt) | stepfun-ai/Step-3.5-Flash | 0.10 | 0.30 |  |  |
| [LangDB](/llm/langdb.txt) | step-3.5-flash |  |  |  | [View](https://langdb.ai/app/models) |
| [ApiYI](/llm/apiyi.txt) | step-3.5-flash |  |  |  |  |
| [OpenRouter](/llm/openrouter.txt) | Step 3.5 Flash (free) | 0.00 | 0.00 | Yes | [View](https://openrouter.ai/stepfun/step-3.5-flash:free) |
| [Airforce API](/llm/airforce.txt) | step-3.5-flash |  |  |  |  |
| [Writingmate](/llm/writingmate.txt) | StepFun: Step 3.5 Flash |  |  |  | [View](https://writingmate.ai/models/stepfun/step-3.5-flash) |
| [LLM Stats](/llm/llmstats.txt) | Step-3.5-Flash |  |  |  |  |

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[← Back to all providers](/llm.txt)