Step 3.5 Flash
language modelStepFun
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....
Key facts
| Made by | StepFun |
|---|---|
| Type | language model |
| Released | January 29, 2026 |
| Reads at once | 262,144 tokens |
| Price (API, per million tokens) | $0.1 in · $0.3 out |
| Input → output | text → text |
Questions about Step 3.5 Flash
Who makes Step 3.5 Flash?
Step 3.5 Flash is made by StepFun.
When was Step 3.5 Flash released?
We first saw Step 3.5 Flash listed on January 29, 2026.
How much does Step 3.5 Flash cost?
Through OpenRouter it costs $0.1 per million input tokens and $0.3 per million output tokens. Prices change, so check the provider before you build on it.
How much text can Step 3.5 Flash read at once?
Up to 262,144 tokens, roughly 196.6K words.
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Modelcast collects this page automatically from public sources (OpenRouter). Facts are copied from those sources, not written by the maker. Not affiliated with StepFun.