Mistral: Mistral Medium 3.5 (batch) vs OpenAI GPT-5.5: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing Mistral: Mistral Medium 3.5 (batch) (mistralai/mistral-medium-3-5:batch) vs OpenAI GPT-5.5 (gpt-5.5). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
Mistral: Mistral Medium 3.5 (batch) (mistralai/mistral-medium-3-5:batch) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for Mistral: Mistral Medium 3.5 (batch): Activate ephemeral prefix caching to slash input costs by 50% (down to $0.375/1M) or route via asynchronous Batch API for 50% off standard token rates.
OpenAI GPT-5.5 (gpt-5.5) Startup Credits & Batch API 50% Off Promo
OpenAI GPT-6.1 Sol ($2/$10 base rate) qualifies for immediate 75% automatic prefix caching ($0.50/1M), 50% off 24-hour Batch API completions ($1/$5), and up to $150,000 in OpenAI/Azure Foundry credits via Microsoft for Startups Founders Hub (no VC funding required for initial tiers).
In Etuki October 2026 FinOps telemetry comparing Mistral: Mistral Medium 3.5 (batch) (API ID: mistralai/mistral-medium-3-5:batch) vs OpenAI GPT-5.5 (API ID: gpt-5.5), Mistral: Mistral Medium 3.5 (batch) offers lower standard input pricing at $0.75/1M tokens ($3.75/1M output), while Mistral: Mistral Medium 3.5 (batch) leads in cached prefix economics at $0.375/1M tokens (50% discount). Mistral: Mistral Medium 3.5 (batch) achieves a 40ms faster P90 time-to-first-token latency (280ms vs 320ms).
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 | Mistral: Mistral Medium 3.5 (batch) | OpenAI GPT-5.5 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | mistralai/mistral-medium-3-5:batch | gpt-5.5 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.75 / $3.75 | $5 / $30 | Mistral: Mistral Medium 3.5 (batch) |
| Cache Read Price (per 1M) | $0.375/1M (50% Off) | $2.5/1M (50% Off) | Mistral: Mistral Medium 3.5 (batch) |
| Context Window / Max Output | 256K In / 205K Out | 1000K In / 128K Out | Mistral: Mistral Medium 3.5 (batch) |
| P90 First-Token / Edge Latency | 280ms | 320ms | Mistral: Mistral Medium 3.5 (batch) (-40ms) |
Mistral Medium 3.5 is a dense 128B instruction-following model from Mistral AI. It supports text and image inputs with text output, and is designed for agentic workflows, coding, a
Flagship GPT-5 series general model with configurable reasoning_effort from none to xhigh.
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 Mistral: Mistral Medium 3.5 (batch) to OpenAI GPT-5.5
Flagship GPT-5 series general model with configurable reasoning_effort from none to xhigh. Verified P90 latency of 320ms.