Question 1

What is Step3's context window?

Accepted Answer

Step3 supports a context window of 65,536 tokens.

Question 2

How much does Step3 cost?

Accepted Answer

Input is $0.57 per million tokens; output is $1.42 per million tokens; according to the OpenRouter catalog..

Question 3

Who makes Step3?

Accepted Answer

Step3 is provided by stepfun-ai. The OpenRouter catalog entry is stepfun-ai/step3.

Question 4

How does Step3 compare with Step 3.5 Flash?

Accepted Answer

Compare Step3 with Step 3.5 Flash for a side-by-side view of their catalog-backed specifications.

Question 5

What is Step3 best for?

Accepted Answer

Step3 is described by stepfun-ai as follows: Step3 is a cutting-edge multimodal reasoning model—built on a Mixture-of-Experts architecture with 321B total parameters and 38B active. It is designed end-to-end to minimize decoding costs while delivering top-tier performance in vision–language reasoning. Through the co-design of Multi-Matrix Factorization Attention (MFA) and Attention-FFN Disaggregation (AFD), Step3 maintains exceptional efficiency across both flagship and low-end accelerators.

Question 6

How can I use Step3 on Krater?

Accepted Answer

Open Step3 in Krater and start a conversation with it alongside hundreds of other AI models.

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