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
256K
Modalities
image, text
Capability Radar
25
general
39
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 |
|---|---|---|---|
| Code Ranking | 121 | 62.0 | AA |
| General Ranking | 109 | 62.0 | AA |
| Science | 77 | 64.0 | 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 Index26.0
Tau20.9
Gpqa0.8
Ifbench0.7
Lcr0.5
Scicode0.4
Terminalbench Hard0.3
Hle0.2
LLM Stats Category Scores
Math90
General90
Reasoning80
Search70
Frontend Development70
Agents70
Tool Calling70
Code60
Pricing
Input Price$0.1 / 1M tokens
Output Price$0.3 / 1M tokens
Blended Price (3:1)$0.15 / 1M tokens
Cache Read Price$0.02 / 1M tokens
Speed
Tokens/sec204.8
Time to First Token0.91s
Time to Answer10.67s
Provider Price Ranking
Provider Price Ranking
11 providers
Cheapest: StepFunMost Expensive: StepFun AI
ProviderInputOutput
1StepFunCheapest
$0
$0
2OpenRouter
$0.09
$0.3
3Vercel AI Gateway
$0.09
$0.3
4NanoGPT
$0.1
$0.3
5SiliconFlow (China)
$0.1
$0.3
6Hugging Face
$0.1
$0.3
7ZenMux
$0.1
$0.3
8Kilo Gateway
$0.1
$0.3
9SiliconFlow
$0.1
$0.3
10routing.run
$0.1
$0.3
11StepFun AI
$0.1
$0.3
Compare pricing across different API providers for this model.