StepFun: Step 3.5 Flash

Name: StepFun: Step 3.5 Flash
Price: 0.3 USD
Author: stepfun

StepFun: Step 3.5 Flash is stepfun's model. It is not yet scored on the meo first-party benchmark; aggregated third-party results and OpenRouter metadata are shown below.

Aggregated third-party benchmarks

Benchmark	Value	Source
AA Coding Index	35	artificial_analysis
AA Intelligence Index	39	artificial_analysis
GPQA Diamond	82.6%	artificial_analysis
Humanity's Last Exam	22.6%	artificial_analysis
IFBench	66.5%	artificial_analysis
LCR (long-context reasoning)	54.3%	artificial_analysis
SciCode	38.5%	artificial_analysis
τ²-bench	87.4%	artificial_analysis
Terminal-Bench Hard	32.6%	artificial_analysis
Median output throughput (tokens/s)	193	artificial_analysis
Median time to first token (s)	1.5	artificial_analysis

Artificial Analysis (artificialanalysis.ai). Redistribution requires an AA commercial license.

Model details

Lab: stepfun
Released: 2026-01-29
Weights: Open
Context: 262K
Max output: 16K
Knowledge cutoff: —
Price in: $0.09/M
Price out: $0.30/M
Modality: text->text

View on OpenRouter ↗Hugging Face ↗

Sources: openrouter · artificial_analysis

FAQ

Is StepFun: Step 3.5 Flash open weights?

Yes — StepFun: Step 3.5 Flash is released with open weights.