StepFun

Step 3.5 Flash

StepFun flash lane for quick multimodal reasoning and coding assistance

stepfun/step-3.5-flash

Context

256K

Output

256K

Released

2026-01-29

Knowledge cutoff

2025-01

Types

InputText

OutputText

Reasoning

Supported

Tool use

Supported

Structured output

—

Attachments

—

Open weights

Supported

Provider pricing

Kilo Gateway

InText

OutText

Price: $0.10 / $0.30
Context: 262.1K
Status: Stable

OpenRouter

InText

OutText

Price: $0.10 / $0.30
Context: 262.1K
Status: Stable

ZenMux

InText

OutText

Price: $0.10 / $0.30
Context: 256K
Status: Stable

Qiniu

InTextImage

OutText

Price: —
Context: 64K
Status: Stable

Provider	Types	Price	Context	Status
Kilo Gateway	InText OutText	$0.10 / $0.30	262.1K	Stable
OpenRouter	InText OutText	$0.10 / $0.30	262.1K	Stable
ZenMux	InText OutText	$0.10 / $0.30	256K	Stable
Qiniu	InTextImage OutText	—	64K	Stable

Benchmarks

Artificial Analysis Coding Index
31.6 · index
SciCode
40.4 · percent correct
Terminal-Bench Hard
27.3 · success rate
SWE-Bench Verified
74.4 · resolved

From the same lab

Step 5 Preview

stepfun/step-5-preview

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stepfun/step-3.7-flash

Step 3.5 Flash 2603

stepfun/step-3.5-flash-2603