Models / stepfun

Step 3.5 Flash

by stepfun · stepfun/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....

reasoningtool-usereleased 2026-01-29

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Legal score · raw

not yet benchmarked

Context

262K

max output 66K

Input

$0.13

per 1M tokens

Output

$0.38

per 1M tokens

Suite cost

no run recorded

Capabilities

Modalities

in text

out text

Request parameters it accepts

frequency_penaltyinclude_reasoningmax_tokensreasoningtemperaturetool_choicetoolstop_ktop_p

Benchmark results

This model has not been run through the suite yet. See Humanity's Last Lawsuit for the benchmark models are ranked on.