Step 3.5 Flash 2603
StepFunOpen WeightApache 2.0 · Commercial OK
Description
Step-3.5-Flash is StepFun's fast, cost-effective text model optimized for quick inference. Built on their Step3 architecture, it offers strong performance across text tasks with low latency and efficient token usage, ideal for production workloads requiring speed and cost efficiency.
Release Date
2026-04-02
Parameters
196.0B
Context Length
262K
Modalities
image, text
Capability Radar
35
general
35
coding
83
reasoning
55
scienceest.
70
agents
80
multimodal
Science uses a reasoning proxy when dedicated science benchmarks are unavailable.
Rankings
| Domain | #Rank | Score | Source |
|---|---|---|---|
| Agents & Tools | 16 | 69.0 | LS |
| Code Ranking | 99 | 61.0 | AA |
| General Ranking | 81 | 72.0 | AA |
| Science | 65 | 67.0 | AA |
Benchmark Scores (LLM Stats)
Agents
Tau-bench
88.2%SR
BrowseComp
69.0%SR
Terminal-Bench 2.0
51.0%SR
Code
SWE-Bench Verified
74.4%SR
General
LiveCodeBench v6
86.4%SR
Math
AIME 2025
97.3%SR
IMO-AnswerBench
85.4%SR
AA Evaluation Indices
Intelligence Index38.5
Coding Index34.6
Tau20.9
Gpqa0.8
Ifbench0.7
Lcr0.5
Scicode0.4
Terminalbench Hard0.3
Hle0.2
LLM Stats Category Scores
General90
Math90
Reasoning80
Tool Calling70
Agents70
Frontend Development70
Search70
Code60
Pricing
Input PriceFree
Output PriceFree
Blended Price (3:1)Free
Speed
Tokens/sec177.7 tokens/s
Time to First Token0.84s
Time to Answer12.10s
Available Providers
(LS internal units)| Provider | Input Price | Output Price |
|---|---|---|
| StepFun | 100K | 400K |