Step 3.5 Flash
stepfun/step-3.5-flashStepFun flash lane for quick multimodal reasoning and coding assistance
Step 3.5 Flash is StepFun's most capable open-source foundation model. Built on a sparse Mixture of Experts (MoE) architecture, it selectively activates only 11B of its 196B parameters per token....
Context
256K
256,000 tokens
Max output
256K
256,000 tokens
Input
$0.10
per 1M tokens
Output
$0.31
per 1M tokens
Providers
14
14 listings
Intelligence
17
Intelligence Index
Pricing
USD per 1M tokens · listed by StepFun (China)
| Token type | Standard |
|---|---|
| Input | $0.10 |
| Output | $0.31 |
| Cache read | $0.02 |
Lowest input price across providers: $0.09.
Capabilities
ReasoningYes
Effort: low, high
Tool callYes
Structured outputYes
TemperatureYes
AttachmentsNo
Interleaved reasoningYes
Field: reasoning_content
Open weightsYes
ModeratedNo
Input
Text
Output
Text
Benchmarks
Published scores and Design Arena Elo
- Intelligence17#113 of 208
- CodingNot scored—
- AgenticNot scored—
- ArenaNot scored—
Rankings
Position on each OneAtlas leaderboard
Providers · 14
14 listings
StepFun (China)
NanoGPT
Kilo Gateway
Eden AI
ZenMux
Qiniu
Hugging Face
CommandCode
EmpirioLabs AI
SiliconFlow
SiliconFlow (China)
StepFun (Global)
StepFun Step Plan (China)
StepFun Step Plan (Global)| Provider | Model ID | Context | Input limit | Output | Input $ | Output $ | Reasoning $ | Cache read | Cache write | Audio in | Audio out | Reasoning | Tools | Structured | Temp. | Updated |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CommandCode | stepfun/Step-3.5-Flash | 256K | 256K | 256K | $0.09 | $0.30 | — | $0.02 | — | — | — | Yes | Yes | Unknown | Yes | Feb 13, 2026 |
| Eden AI | deepinfra/stepfun-ai/Step-3.5-Flash | 262K | — | 256K | $0.09 | $0.30 | — | $0.02 | — | — | — | Yes | Yes | Yes | Yes | Feb 13, 2026 |
| EmpirioLabs AI | step-3-5-flash | 256K | 256K | 131K | $0.10 | $0.30 | — | $0.02 | — | — | — | Yes | Yes | No | Yes | Feb 13, 2026 |
| Hugging Face | stepfun-ai/Step-3.5-Flash | 262K | — | 256K | $0.10 | $0.30 | — | — | — | — | — | Yes | Yes | Unknown | Yes | Feb 13, 2026 |
| Kilo Gateway | stepfun/step-3.5-flash | 262K | — | 66K | $0.10 | $0.30 | — | — | — | — | — | Yes | Yes | No | Yes | Feb 13, 2026 |
| NanoGPT | stepfun-ai/step-3.5-flash | 262K | 262K | 66K | $0.10 | $0.30 | — | $0.05 | — | — | — | Yes | No | No | Yes | Feb 13, 2026 |
| Qiniu | stepfun/step-3.5-flash | 64K | 256K | 4K | — | — | — | — | — | — | — | No | No | No | Yes | Feb 13, 2026 |
| SiliconFlow | stepfun-ai/Step-3.5-Flash | 262K | — | 66K | $0.10 | $0.30 | — | — | — | — | — | Yes | Yes | Yes | Yes | Feb 13, 2026 |
| SiliconFlow (China) | stepfun-ai/Step-3.5-Flash | 262K | — | 262K | $0.10 | $0.31 | — | — | — | — | — | Yes | Yes | Yes | Yes | Feb 13, 2026 |
| StepFun (China) | step-3.5-flash | 256K | 256K | 256K | $0.10 | $0.31 | — | $0.02 | — | — | — | Yes | Yes | Yes | Yes | Feb 13, 2026 |
| StepFun (Global) | step-3.5-flash | 256K | 256K | 256K | $0.10 | $0.30 | — | $0.02 | — | — | — | Yes | Yes | Yes | Yes | Feb 13, 2026 |
| StepFun Step Plan (China) | step-3.5-flash | 256K | 256K | 256K | — | — | — | — | — | — | — | Yes | Yes | Yes | Yes | Feb 13, 2026 |
| StepFun Step Plan (Global) | step-3.5-flash | 256K | 256K | 256K | — | — | — | — | — | — | — | Yes | Yes | Unknown | Yes | Feb 13, 2026 |
| ZenMux | stepfun/step-3.5-flash | 256K | — | 256K | $0.10 | $0.30 | — | — | — | — | — | Yes | Yes | Unknown | Yes | Feb 13, 2026 |