How much does Step 3.5 Flash (free) cost?

Step 3.5 Flash (free) costs $0.00 per million input tokens and $0.00 per million output tokens. For a typical conversation (~2,000 tokens), that's approximately $0.000 per message.

What benchmarks has Step 3.5 Flash (free) been tested on?

Step 3.5 Flash (free) has not been benchmarked yet. Scores are added as benchmarks are published.

Is Step 3.5 Flash (free) open source?

Yes, Step 3.5 Flash (free) is open source.

How does Step 3.5 Flash (free) compare to 3b De Ft Research_release?

Step 3.5 Flash (free) has an average score of 0.0 while 3b De Ft Research_release scores 0.0. 3b De Ft Research_release slightly outperforms Step 3.5 Flash (free) overall. See full comparison →

Home/Models/Step 3.5 Flash (free)

Step 3.5 Flash (free)

Name: Step 3.5 Flash (free)
Author: stepfun

by stepfun · Released Jan 2026

Open Source

Compare

Context

256K tokens (~128 books)

Input $/1M

Free

Output $/1M

Free

Type

text

License

Open Source

Benchmarks

0 tested

Data updated today

About

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. It is a reasoning model that is incredibly speed efficient even at long contexts.

No benchmark data available yet.

Model Family · stepfun Step 3.5

Step 3.5 FlashJan 2026

76.9

$0.10/M in262Kctx10 benchmarks

Step 3.5 Flash (free)Jan 2026

$0.00/M in(-0.10)256Kctx(-6K)

See the full Step 3.5 family →

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