Step 3.5 Flash

Name: Step 3.5 Flash
Brand: StepFun
Price: 0.1 USD

byStepFun

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....

Chat withStep 3.5 Flash

Input Price$0.10/1M tokens

Output Price$0.30/1M tokens

Intelligence37.8

Coding31.6

Specifications

Technical details and pricing.

ProviderStepFun

Context Window262,144 tokens

Release DateFeb 2, 2026

ModalitiesText

Benchmarks

7 benchmark scores from Artificial Analysis.

GPQA83.1%

HLE19.1%

SciCode40.4%

LCR43.0%

IFBench64.6%

Tau294.4%

TerminalBench Hard27.3%

Composite Indices

Intelligence, Coding, Math

Standard Benchmarks

Academic and industry benchmarks

Frequently Asked Questions

What is Step 3.5 Flash good for?

Use Step 3.5 Flash for everyday tasks like writing, summarizing, brainstorming, and getting clear explanations.

How much does Step 3.5 Flash cost?

Pricing is based on usage. Current rates are $0.10/1M tokens for input and $0.30/1M tokens for output.

Can I try Step 3.5 Flash for free?

Yes. You can start a chat instantly and test the model before deciding on a plan.

Does Step 3.5 Flash support images or audio?

Step 3.5 Flash focuses on text-based tasks.

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Benchmarks and pricing are sourced from Artificial Analysis where available. OpenRouter specs are used as a fallback.