ST

Step 3.5 Flash

Chat model

Step 3.5 Flash

Release date: 2026-02-02Updated: 2026-03-08 21:06:203,139
Parameters
196B
Context length
256K
Chinese support
Supported
Reasoning ability

Step 3.5 Flash is an AI model published by StepFunAI, released on 2026-02-02, for Chat model, with 196B parameters, and 256K context length, requiring about 399GB storage, under the Apache 2.0 license, with a 99.80 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

Step 3.5 Flash

Model basics

Reasoning traces
Supported
Thinking modes
Standard Mode
Context length
256K tokens
Max output length
16K tokens
Model type
Chat model
Modality (in / out)
Text → Text
Release date
2026-02-02
Model file size
399GB
MoE architecture
Yes
Total params / Active params
196B / 11B
Knowledge cutoff
No data
Step 3.5 Flash

Open source & experience

Code license
Weights license
Apache 2.0- 免费商用授权
Live demo
No live demo
Step 3.5 Flash

Official resources

DataLearnerAI blog
Step 3.5 Flash

API details

API speed
5/5
No public API pricing yet.
Step 3.5 Flash

Benchmark Results

Step 3.5 Flash currently shows benchmark results led by AIME2025 (6 / 106, score 99.80), LiveCodeBench (13 / 120, score 86.40), τ²-Bench (5 / 40, score 88.20). 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
Tool usage

General Knowledge

2 evaluations
Benchmark / mode
Score
Rank/total
56.50
39 / 65
53.50
42 / 65

Coding and Software Engineer

2 evaluations
Benchmark / mode
Score
Rank/total
86.40
13 / 120
74.40
38 / 108

Math and Reasoning

4 evaluations
Benchmark / mode
Score
Rank/total
99.80
6 / 106
97.30
18 / 106
86.70
6 / 20
85.40
8 / 20

Agent Level Benchmark

1 evaluations
Benchmark / mode
Score
Rank/total
88.20
5 / 40

AI Agent - Information Search

1 evaluations
Benchmark / mode
Score
Rank/total
69
22 / 45

AI Agent - Tool Usage

1 evaluations
Benchmark / mode
Score
Rank/total

Claw-style Agent Evaluation

2 evaluations
Benchmark / mode
Score
Rank/total
Pinch Bench
Thinking ModeTools
85.30
15 / 37
Claw Bench
Thinking ModeTools
84.90
16 / 29

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Step 3.5 Flash

Publisher

Step 3.5 Flash

Model Overview

Step 3.5 Flash is an AI model published by StepFunAI, released on 2026-02-02, for Chat model, with 196B parameters, and 256K context length, requiring about 399GB storage, under the Apache 2.0 license, with a 99.80 score on AIME2025.

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