ST

Step3

Multimodal model

Step3-321B-A38B

Release date: 2025-07-31Updated: 2025-08-04 17:05:47789
Parameters
321B
Context length
64K
Chinese support
Supported
Reasoning ability

Step3-321B-A38B is an AI model published by StepFunAI, released on 2025-07-31, for Multimodal model, with 321B parameters, and 64K context length, requiring about 642GB storage, under the Apache 2.0 license, with a 82.90 score on AIME2025.

Data sourced primarily from official releases (GitHub, Hugging Face, papers), then benchmark leaderboards, then third-party evaluators. Learn about our data methodology

Step3

Model basics

Reasoning traces
Not supported
Thinking modes
Thinking modes not supported
Context length
64K tokens
Max output length
No data
Model type
Multimodal model
Modality (in / out)
Text → Video
Release date
2025-07-31
Model file size
642GB
MoE architecture
Yes
Total params / Active params
321B / 38B
Knowledge cutoff
No data
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Open source & experience

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Official resources

DataLearnerAI blog
No blog post yet
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API details

API speed
4/5
No public API pricing yet.
Step3

Benchmark Results

Step3 currently shows benchmark results led by LiveCodeBench (56 / 120, score 67.10), SimpleVQA (1 / 2, score 62.20), AIME2025 (53 / 106, score 82.90). This page also consolidates core specs, context limits, and API pricing so you can evaluate the model from benchmark results and deployment constraints together.

Thinking

General Knowledge

1 evaluations
Benchmark / mode
Score
Rank/total
73
102 / 179

Coding and Software Engineer

1 evaluations
Benchmark / mode
Score
Rank/total
67.10
56 / 120

Math and Reasoning

1 evaluations
Benchmark / mode
Score
Rank/total
82.90
53 / 106

Multimodal Understanding

2 evaluations
Benchmark / mode
Score
Rank/total
74.20
17 / 28
62.20
1 / 2

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Step3

Model variants & downloads

Variant nameVersion typeQuantizationModel sizeHuggingFace link
Step3-FP8ℹ️InstructFP8327.11 GBDownload link
Step3

Publisher

Step3-321B-A38B

Model Overview

Step3-321B-A38B is an AI model published by StepFunAI, released on 2025-07-31, for Multimodal model, with 321B parameters, and 64K context length, requiring about 642GB storage, under the Apache 2.0 license, with a 82.90 score on AIME2025.

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