Models/StepFun/Step 3.5 Flash

Step 3.5 Flash

StepFun · Open weights · Released Jan 29, 2026 · stepfun/step-3.5-flash
Best $0.10 in / $0.30 out via SiliconFlow · fp8
CompareEstimate cost
262K contextToolsReasoningOpen weights
Available from 1 providerUSD / MTOK · PRICES 23 MINUTES AGO · SPEED 2 DAYS AGO
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PROVIDERINPUTOUTPUTCACHECONTEXTQUANTTTFTTPSUPTIME
TTFT/TPS: median (P50) over trailing 504h · chat10k profile (~10K in / 200 out) · measured via OpenRouter routing · ✕ = probed, endpoint returned no measurable stream · methodology v1.1 · measured 2 days ago
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About

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....

Specifications
Context window262,144
Max output65,536
Modalities intext
Modalities outtext
LicenseOpen weights
ReleasedJan 29, 2026
TokenizerOther
WeightsHugging Face ↗
Open weights
Hugging Facestepfun-ai/Step-3.5-Flash ↗
Downloads215.4K
Likes838
Licenseapache-2.0
safetensors
Related
Step 3.7 Flash$0.20 / $1.15
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[![Step 3.5 Flash](https://modelindex.ai/badge/stepfun/step-3.5-flash)](https://modelindex.ai/models/stepfun/step-3.5-flash)
Sources
OpenRouter API23 minutes ago
AGGREGATOR
Hugging Face23 minutes ago
COMMUNITY
ModelIndex benchmarks2 days ago
MEASURED
Verified 23 minutes ago · list prices, not negotiated rates.