Question 1

What does this Step 5 Preview vs Step 3.7 Flash comparison cover?

Accepted Answer

It brings together documented inputs and outputs, token limits, deployment terms and available pricing. When both models have source-linked, verified results on a shared benchmark, those results are shown with their individual sources. The comparison is a starting point for evaluating your own workload.

Question 2

Which is cheaper: Step 5 Preview or Step 3.7 Flash?

Accepted Answer

Step 5 Preview lists $1.00 input and $2.70 output per 1M tokens. Step 3.7 Flash lists $0.185 input and $1.11 output. The cheaper workload depends on the mix of input and output. Long-context tiers, caching, batch processing and retries can change the bill.

Question 3

Which has the larger context window: Step 5 Preview or Step 3.7 Flash?

Accepted Answer

Step 5 Preview lists 1M tokens and Step 3.7 Flash lists 256K. Step 5 Preview therefore has the larger recorded context window, but capacity alone is not a quality score.

Question 4

Which is faster: Step 5 Preview or Step 3.7 Flash?

Accepted Answer

There is no matched speed measurement for both models with the same source, host, region and date. Test the same prompts at your expected concurrency and measure time to the first useful response as well as complete task time.

Question 5

What input and output types do Step 5 Preview and Step 3.7 Flash support?

Accepted Answer

Step 5 Preview records text, image, video input and text output. Step 3.7 Flash records text, image, video input and text output. “Not documented” means the current source record is incomplete; it does not prove that a modality is unsupported.

Question 6

Should I choose Step 5 Preview or Step 3.7 Flash?

Accepted Answer

Consider Step 5 Preview if you need larger context. Consider Step 3.7 Flash if you need larger maximum output or a lower listed input rate or a lower listed output rate. Step 3.7 Flash offers downloadable weights; Step 5 Preview is listed as a proprietary model. Compare licence terms and operating costs before choosing a deployment. Test both on the same representative examples and judge the output against your acceptance criteria. Include tool failures, retries and the time to a completed task.

Specification	Step 5 Preview	Step 3.7 Flash
Provider	StepFun	StepFun
Listed pricing route	StepFun	StepFun
Model family	—	—
Accepted inputs	text, image, video	text, image, video
Produced outputs	text	text
Context window	1MHigher	256K
Max output	65.54K	256KHigher
Input price / 1M	$1.00	$0.185Lower
Output price / 1M	$2.70	$1.11Lower
Reasoning mode	Documented	Documented
Tool calling	Documented	Documented
Image input	Documented	Documented
Audio input	Not documented	Not documented
Structured output	Documented	Not documented
License	Publisher API terms	Open weights

Step 5 Preview vs Step 3.7 Flash

Step 5 Preview

Step 3.7 Flash

Key differences

Pricing, limits and capabilities

Which model should you choose?

Documentation and model profiles

Questions people ask

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