Mistral: Mistral Medium 3.5 vs xAI Grok 4.3: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing Mistral: Mistral Medium 3.5 (mistralai/mistral-medium-3-5) vs xAI Grok 4.3 (grok-4.3). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
Mistral: Mistral Medium 3.5 (mistralai/mistral-medium-3-5) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for Mistral: Mistral Medium 3.5: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.75/1M) or route via asynchronous Batch API for 50% off standard token rates.
xAI Grok 4.3 (grok-4.3) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for xAI Grok 4.3: Activate ephemeral prefix caching to slash input costs by 50% (down to $1/1M) or route via asynchronous Batch API for 50% off standard token rates.
In Etuki October 2026 FinOps telemetry comparing Mistral: Mistral Medium 3.5 (API ID: mistralai/mistral-medium-3-5) vs xAI Grok 4.3 (API ID: grok-4.3), Mistral: Mistral Medium 3.5 offers lower standard input pricing at $1.5/1M tokens ($7.5/1M output), while Mistral: Mistral Medium 3.5 leads in cached prefix economics at $0.75/1M tokens (50% discount). xAI Grok 4.3 achieves a 100ms faster P90 time-to-first-token latency (180ms 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 | Mistral: Mistral Medium 3.5 | xAI Grok 4.3 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | mistralai/mistral-medium-3-5 | grok-4.3 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $1.5 / $7.5 | $2 / $10 | Mistral: Mistral Medium 3.5 |
| Cache Read Price (per 1M) | $0.75/1M (50% Off) | $1/1M (50% Off) | Mistral: Mistral Medium 3.5 |
| Context Window / Max Output | 256K In / 205K Out | 512K In / 128K Out | Mistral: Mistral Medium 3.5 |
| P90 First-Token / Edge Latency | 280ms | 180ms | xAI Grok 4.3 (-100ms) |
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
xAI October 2026 frontier reasoning model with live X/Web grounding and sub-200ms latency.
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 to xAI Grok 4.3
xAI October 2026 frontier reasoning model with live X/Web grounding and sub-200ms latency. Verified P90 latency of 180ms.