DeepSeek: DeepSeek V3.1 vs Qwen: Qwen3.5 Plus 2026-04-20: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing DeepSeek: DeepSeek V3.1 (deepseek/deepseek-chat-v3.1) vs Qwen: Qwen3.5 Plus 2026-04-20 (qwen/qwen3.5-plus-20260420). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
DeepSeek: DeepSeek V3.1 (deepseek/deepseek-chat-v3.1) — Automatic Disk KV Cache ($0.125/1M) & 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.
Qwen: Qwen3.5 Plus 2026-04-20 (qwen/qwen3.5-plus-20260420) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for Qwen: Qwen3.5 Plus 2026-04-20: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.15/1M) or route via asynchronous Batch API for 50% off standard token rates.
In Etuki October 2026 FinOps telemetry comparing DeepSeek: DeepSeek V3.1 (API ID: deepseek/deepseek-chat-v3.1) vs Qwen: Qwen3.5 Plus 2026-04-20 (API ID: qwen/qwen3.5-plus-20260420), DeepSeek: DeepSeek V3.1 offers lower standard input pricing at $0.25/1M tokens ($0.95/1M output), while DeepSeek: DeepSeek V3.1 leads in cached prefix economics at $0.125/1M tokens (50% discount). DeepSeek: DeepSeek V3.1 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 | DeepSeek: DeepSeek V3.1 | Qwen: Qwen3.5 Plus 2026-04-20 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | deepseek/deepseek-chat-v3.1 | qwen/qwen3.5-plus-20260420 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.25 / $0.95 | $0.3 / $1.8 | DeepSeek: DeepSeek V3.1 |
| Cache Read Price (per 1M) | $0.125/1M (50% Off) | $0.15/1M (50% Off) | DeepSeek: DeepSeek V3.1 |
| Context Window / Max Output | 160K In / 32K Out | 977K In / 64K Out | Qwen: Qwen3.5 Plus 2026-04-20 |
| P90 First-Token / Edge Latency | 280ms | 280ms | DeepSeek: DeepSeek V3.1 (-0ms) |
DeepSeek-V3.1 is a large hybrid reasoning model (671B parameters, 37B active) that supports both thinking and non-thinking modes via prompt templates. It extends the DeepSeek-V3 ba
Qwen3.5 Plus (April 2026) is a large-scale multimodal language model from Alibaba. It accepts text, image, and video input and produces text output, with a 1M token context window.
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 DeepSeek: DeepSeek V3.1 to Qwen: Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus (April 2026) is a large-scale multimodal language model from Alibaba. It accepts text, image, and video input and produces text output, with a 1M token context window. Verified P90 latency of 280ms.