Step 3.5 Flash
Step 3.5 Flash is StepFun's language model with a 262K context window and up to 16K output tokens, starting at $0.090 / 1M input and $0.300 / 1M output. An open-source Mixture-of-Experts reasoning model from StepFun with 196B total parameters (11B active), featuring a 256K context window and tool-calling support.
Capabilities
Input1/5
Text✓
Image·
Audio·
Video·
PDF·
Output1/5
Text✓
Image·
Audio·
Video·
Embedding·
Capabilities3/13
Reasoning✓
Adaptive Reasoning·
Function Calling✓
Parallel Function Calling·
Structured Outputs✓
Native JSON Schema·
Web Search·
URL Context·
Computer Use·
Code Execution·
File Search·
Prompt Caching·
Assistant Prefill·
Pricing by Provider
| Provider | Standard | ||
|---|---|---|---|
| Input $ / 1M | Output $ / 1M | Cache Read $ / 1M | |
 OpenRouter | $0.090 | $0.300 | $0.020 |
Cost Calculator
Preset: