StepFun: Step 3.7 Flash vs StepFun: Step 5 Preview: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing StepFun: Step 3.7 Flash (stepfun/step-3.7-flash) vs StepFun: Step 5 Preview (stepfun/step-5-preview). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
StepFun: Step 3.7 Flash (stepfun/step-3.7-flash) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for StepFun: Step 3.7 Flash: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.1/1M) or route via asynchronous Batch API for 50% off standard token rates.
StepFun: Step 5 Preview (stepfun/step-5-preview) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for StepFun: Step 5 Preview: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.5/1M) or route via asynchronous Batch API for 50% off standard token rates.
In Etuki October 2026 FinOps telemetry comparing StepFun: Step 3.7 Flash (API ID: stepfun/step-3.7-flash) vs StepFun: Step 5 Preview (API ID: stepfun/step-5-preview), StepFun: Step 3.7 Flash offers lower standard input pricing at $0.2/1M tokens ($1.15/1M output), while StepFun: Step 3.7 Flash leads in cached prefix economics at $0.1/1M tokens (50% discount). StepFun: Step 3.7 Flash achieves a 0ms faster P90 time-to-first-token latency (280ms vs 280ms).
Auto-discovered via live global telemetry registry.
Auto-discovered via live global telemetry registry.
| Specification / FinOps Dimension | StepFun: Step 3.7 Flash | StepFun: Step 5 Preview | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | stepfun/step-3.7-flash | stepfun/step-5-preview | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.2 / $1.15 | $1 / $2.7 | StepFun: Step 3.7 Flash |
| Cache Read Price (per 1M) | $0.1/1M (50% Off) | $0.5/1M (50% Off) | StepFun: Step 3.7 Flash |
| Context Window / Max Output | 256K In / 225K Out | 1024K In / 63K Out | StepFun: Step 3.7 Flash |
| P90 First-Token / Edge Latency | 280ms | 280ms | StepFun: Step 3.7 Flash (-0ms) |
Step 3.7 Flash is StepFun's latest high-efficiency multimodal Mixture-of-Experts model. It pairs a 196B-parameter language backbone with a vision encoder for native image and video
Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in softwar
Real-Time Stack Cost & Hidden-Fee Simulator (MAU / Token / Egress / GMV)
Calibrated with Reddit r/FinOps & r/devops telemetry: Includes Context Caching, Bandwidth Egress, and MoR Tax
🛰️Switch from StepFun: Step 3.7 Flash to StepFun: Step 5 Preview
Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in softwar Verified P90 latency of 280ms.