Step 3.5 Flash 2603
Step 3.5 Flash 2603 is an open-weights language model from StepFun, released February 2, 2026. The context window is 250K tokens. API price: $0.1 input / $0.31 output per million tokens.
Check it against your own PC →
Lab
StepFun
Released
February 2, 2026
Weights
Open
Parameters
–
Context
250K
Price / M tokens
$0.1 / $0.31 in / out
Epoch ECI
not yet rated
Can you run Step 3.5 Flash 2603 locally?
Even with 32 GB of VRAM and 32 GB of RAM it is too large to run at a usable speed on a single consumer GPU. Estimates assume 32 GB of DDR5 RAM, a 16K context and llama.cpp-style GGUF quantization. Enter your exact hardware in the live app.
| GPU memory | Verdict | Best quant | VRAM | RAM | tok/s |
|---|---|---|---|---|---|
| 6 GB VRAM | Size unknown | – | – | – | – |
| 8 GB VRAM | Size unknown | – | – | – | – |
| 12 GB VRAM | Size unknown | – | – | – | – |
| 16 GB VRAM | Size unknown | – | – | – | – |
| 24 GB VRAM | Size unknown | – | – | – | – |
| 32 GB VRAM | Size unknown | – | – | – | – |
Parameter count unknown. The weights may not be on Hugging Face yet.
Benchmark results
Epoch AI has not published results for Step 3.5 Flash 2603 yet. New models are usually evaluated within days to weeks.