StepfunfastVisionTool use

Step 3.7 Flash

Step 3.7 Flash is StepFun's latest high-efficiency multimodal Mixture-of-Experts model. It pairs a 196B-parameter language backbone with a vision encoder for native image and video understanding, activating roughly 11B parameters...

256K context·~192K words·256K max output

View context details Compare with Jp Anthropic Claude Sonnet 4 6

Context window256Ktokens

Max output256Ktokens

Context window

This model accepts 256K tokens in one request (~192K words of text).

Context window size256K tokens

4K32K128K1M10M

What fits in one request

Short document
About 1,500 words of text
Fits
Long document
About 37K words of text
Fits
Small codebase
About 150K words of text
Fits
Full novel
About 375K words of text
Won't fit

Specifications

Context size, pricing, and release info in one place.

Context window: 256,000 tokens (256K)
Max output tokens: 256,000 tokens (256K)
Speed tier: fast
Provider: Stepfun
Release date: May 2026

Capabilities

See which features this model supports, such as vision, tools, and streaming.

Supported (6)

Vision: Accepts image inputs alongside text; Supported
Tool use: Can call external tools and APIs; Supported
Function calling: Structured function call interface; Supported
Extended thinking: Shows its chain-of-thought reasoning; Supported
Streaming: Returns tokens as they are generated; Supported
Prompt caching: Reuse repeated prompt prefixes cheaply; Supported

Not supported (2)

Web search: Can browse the web during a request; Not supported
Batch API: Process many requests asynchronously; Not supported

Best for

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Reasoning AI agents Multimodal Long documents RAG Chatbots

Compare Step 3.7 Flash

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Frequently asked questions

Short answers about context size and how this model behaves.

Step 3.7 Flash has a context window of 256K tokens (256,000 tokens). This large window is well-suited for long document analysis, extensive codebases, and multi-session agent workflows.

More from Stepfun

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Example: a multi-turn chat session

Without Mem0~128K tokens sent

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Key memories

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