step-3.5-flash
Model overview
step-3.5-flash-2603
StepFun step-3.5-flash reasoning model.
general LLMreasoninglong contextchatsoftware engineering agententerprise access
Representative version
step-3.5-flash-2603
| Company | StepFun |
|---|---|
| Release | 2026-03-01 |
| Release type | Model release |
| Parameters | Not disclosed |
| Architecture | Not disclosed |
| Context | 262,144 |
| Input modalities | text / image / video |
| Output modalities | text / code / tool_call |
| Tool use / function calling | Confirmed: Tool use, Function calling |
| Structured output / reasoning | Confirmed: Reasoning |
| Vision / audio / video | Confirmed: Vision, Video |
| Open weights / License | No open weights currently / weight license not disclosed stepfun-step-3-5-flash-2603 · License not applicable |
| Vendor API | Available StepFun API pricing and supported modelsstepfun-step-3-5-flash-2603 · 2026-03-01 |
| OpenRouter | Not separately listed on OpenRouter |
| Pricing | No reliable public source |
| Benchmark | LMArena 2 rows |
| Public signals | 1 runtime / access record / 1 activity snapshot |
| Use cases | Multimodal assistants / coding and review / Agent workflows / assistant chat |
| Claim evidence | Release event / Model specificationsStepFun API pricing and supported modelsstep-3.5-flash-2603 · 2026-03-01 · step-3.5-flash · step-3.5-flash-2603 |
OpenRouter
Pricing / context / availability
| OpenRouter | Not separately listed on OpenRouter |
|---|---|
| OpenRouter listing | Not separately listed in the current OpenRouter public list |
| Mapped version | step-3.5-flash-2603 stepfun-step-3-5-flash-2603 |
| Pricing | No reliable public source |
| Context | 262144 |
| Speed/Latency | No reliable public source |
| Snapshot time | 2026-08-11T06:28:09.895Z |
| Source | View source |
Benchmark
Ranking evidence
| Source | Task | Rank | Score | Sample | Time | Link |
|---|---|---|---|---|---|---|
| LMArena | Coding | 102 | 1,448.09 | 5,677 | 2026-05-07 | View source |
| LMArena | Text overall | 119 | 1,393.27 | 25,112 | 2026-05-07 | View source |
Verified limitations
Usage boundaries
- Listed through Step Plan and pricing rather than the five-model public overview.
Public activity counters
Hugging Face model-card activity snapshot
| Platform | Entry | Last-month downloads | Current likes | Current Spaces | Time | Source |
|---|---|---|---|---|---|---|
| huggingface Current HF activity snapshot | stepfun-ai/Step-3.5-Flash | 127,762 | 830 | 88 | View source |
Downloads are Hugging Face's trailing-month counter; likes and Spaces are snapshots at collection time.
Operations
Runtime / access signals
| Time | Signal | Original text | Source |
|---|---|---|---|
| 05/26/2026, 01:36 PM UTC | Questions re: config.json | Was running modelingstep3p5.py via huggingface, and I kept running into the error: In SafeTensors there seem to be 48 layers. I fixed this by... | Source |
Vertical comparison
Current available versions
| Version | Release | Parameters | Context | Input | Output | Open weights / License | Vendor API | Source tier |
|---|---|---|---|---|---|---|---|---|
| step-3.5-flash-2603 | 2026-03-01 | Not disclosed | 262,144 | text / image / video | text / code / tool_call | No open weights currently / weight license not disclosed | Available | Official source |
| step-3.5-flash | Not disclosed | 196.81B / 11B active | 256,000 | text / code | text / code | Weight status not disclosed / license not disclosed | Available | Official source |
Missing public information
Public information not yet available
Parameter scale not disclosedNot listed on OpenRouterNo linkable model-specific reviewSpeed/latency not disclosed