Step 3.5 Flash
StepFun · 1 configuration
Intelligence16.6
Input / 1M$0.10
Output / 1M$0.30
Context256K
Tariff: StepFun · Source: artificial-analysis · USD per million tokens
Thinking configuration
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Compare this model’s measured thinking configurations.
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Efficient frontier: best measured score at each cost1 measured configurations · 0 without both values
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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....
Intelligence IndexArtificial Analysis composite index, not a percentage. Different versions of the index are not directly comparable.
16.6 pointsGPQA DiamondGraduate-level scientific questions. Measures specialist reasoning rather than web-search quality.
83.1 %Humanity’s Last ExamDifficult questions across many disciplines, compared under the same evaluation setup.
21.1 %τ²-BenchTool use and interaction in assistance scenarios. Does not replace an evaluation of your integration.
94.4 %IFBenchVerifiable instruction following. A proxy for precision rather than a benchmark of creative style.
64.6 %Omniscience accuracyFactual accuracy in Artificial Analysis's Omniscience evaluation.
23.6 %Specifications from the catalog
Inputtext
Outputtext
Tool callingYes
Structured outputNo
Speed143.0 tok/s
First token3.43 s
Maximum output65.5K
Catalog listing date2026-01-29