StepFun: Step 5 Preview vs DeepSeek-V4 Flash: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing StepFun: Step 5 Preview (stepfun/step-5-preview) vs DeepSeek-V4 Flash (deepseek-v4-flash). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
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.
DeepSeek-V4 Flash (deepseek-v4-flash) — Automatic Disk KV Cache ($0.035/1M) & Off-Peak Promo
DeepSeek-V4 Pro (1.6T MoE) automatically caches repeated 64-token prompt prefixes on NVMe storage at $0.07/1M input tokens (50% off $0.14 base) with zero code changes required, plus off-peak UTC scheduling discounts.
In Etuki October 2026 FinOps telemetry comparing StepFun: Step 5 Preview (API ID: stepfun/step-5-preview) vs DeepSeek-V4 Flash (API ID: deepseek-v4-flash), DeepSeek-V4 Flash offers lower standard input pricing at $0.07/1M tokens ($0.14/1M output), while DeepSeek-V4 Flash leads in cached prefix economics at $0.035/1M tokens (50% discount). DeepSeek-V4 Flash achieves a 40ms faster P90 time-to-first-token latency (240ms vs 280ms).
Auto-discovered via live global telemetry registry.
Enable Prompt Context Caching & Batch API to reduce repeated system prompt input token burn by 50%-97.5%.
| Specification / FinOps Dimension | StepFun: Step 5 Preview | DeepSeek-V4 Flash | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | stepfun/step-5-preview | deepseek-v4-flash | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $1 / $2.7 | $0.07 / $0.14 | DeepSeek-V4 Flash |
| Cache Read Price (per 1M) | $0.5/1M (50% Off) | $0.035/1M (50% Off) | DeepSeek-V4 Flash |
| Context Window / Max Output | 1024K In / 63K Out | 1000K In / 64K Out | DeepSeek-V4 Flash |
| P90 First-Token / Edge Latency | 280ms | 240ms | DeepSeek-V4 Flash (-40ms) |
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
284B parameter (13B active) high-speed sparse-attention model with thinking integrated directly into tool calls.
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 5 Preview to DeepSeek-V4 Flash
284B parameter (13B active) high-speed sparse-attention model with thinking integrated directly into tool calls. Verified P90 latency of 240ms.