OpenAI GPT-5.5 vs OpenAI GPT-6 Luna: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing OpenAI GPT-5.5 (gpt-5.5) vs OpenAI GPT-6 Luna (gpt-6-luna). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
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).
OpenAI GPT-6 Luna (gpt-6-luna) 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 OpenAI GPT-5.5 (API ID: gpt-5.5) vs OpenAI GPT-6 Luna (API ID: gpt-6-luna), OpenAI GPT-6 Luna offers lower standard input pricing at $0.1/1M tokens ($0.5/1M output), while OpenAI GPT-6 Luna leads in cached prefix economics at $0.025/1M tokens (75% discount). OpenAI GPT-6 Luna achieves a 175ms faster P90 time-to-first-token latency (145ms vs 320ms).
Enable Prompt Context Caching & Batch API to reduce repeated system prompt input token burn by 50%-97.5%.
Enable Prompt Context Caching & Batch API to reduce repeated system prompt input token burn by 50%-97.5%.
| Specification / FinOps Dimension | OpenAI GPT-5.5 | OpenAI GPT-6 Luna | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | gpt-5.5 | gpt-6-luna | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $5 / $30 | $0.1 / $0.5 | OpenAI GPT-6 Luna |
| Cache Read Price (per 1M) | $2.5/1M (50% Off) | $0.025/1M (75% Off) | OpenAI GPT-6 Luna |
| Context Window / Max Output | 1000K In / 128K Out | 1000K In / 64K Out | OpenAI GPT-5.5 |
| P90 First-Token / Edge Latency | 320ms | 145ms | OpenAI GPT-6 Luna (-175ms) |
Flagship GPT-5 series general model with configurable reasoning_effort from none to xhigh.
OpenAI ultra-affordable reasoning and logic model with 1M+ token context window for high-volume production pipelines.
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 OpenAI GPT-5.5 to OpenAI GPT-6 Luna
OpenAI ultra-affordable reasoning and logic model with 1M+ token context window for high-volume production pipelines. Verified P90 latency of 145ms.