StepFun
Chat with Step 3.7 Flash online
StepFun's efficiency model — Apache 2.0, fast enough to call in a loop and capable enough to trust.
262.144K tokens
Context
131,072 tokens
Max output
Fast
Speed
What you’ll use it for
High-volume agents
Loops where latency and price compound quickly.
Everyday coding
Fast answers on real code without the frontier price.
Search workflows
Reading and filtering a lot of material quickly.
Structured output
Clean JSON when the answer feeds a pipeline.
Prompts to steal
Tuned to this model — click any line to copy.
About Step 3.7 Flash
Step 3.7 Flash is StepFun's efficiency model, released on 28 May 2026 under an Apache 2.0 licence. It is a sparse mixture-of-experts design of about 198 billion parameters that activates only around 11 billion per token, which is the whole point: it answers quickly and costs little, while staying capable enough for real work.
StepFun built it for coding agents and search-style workflows — the kind of job where a model is called many times in a loop and both latency and price compound. Throughput runs to several hundred tokens a second on a good rail, and the model exposes selectable reasoning levels so a caller can trade depth against speed per request rather than being locked into one setting. It takes tools and tool_choice for function calling and supports a JSON response format when the output feeds a pipeline.
The value claim is the interesting part. On SWE-Bench Verified with its advisor mode enabled, StepFun reports Step 3.7 Flash reaching around 97% of a frontier model's coding score at roughly a ninth of the per-task cost. Treat any single benchmark carefully, but the shape of the claim matches what the architecture is for.
The context window is 262,144 tokens, so a substantial codebase or a long document set fits in one conversation. On NinjaChat it is included in every plan — a good default when you want a capable model to answer fast and often.
How to use Step 3.7 Flash
From zero to your first result in under a minute.
01
Create a NinjaChat account and choose a plan
02
Open chat and pick Step 3.7 Flash from the model list
03
Use it as your default for fast, frequent questions
04
Escalate to a frontier model when a task gets hard
Tips for better results
- Great as the first pass before a bigger model
- Ask for JSON when the answer feeds something else
- Its context is large; paste the whole file
- Pair it with a frontier model rather than replacing one
Questions, answered.
Beyond chat — images & video
The same subscription covers the image studio and video generation.
Step 3.7 Flash, and 50 more.
One subscription covers every model on NinjaChat, Step 3.7 Flash included.
