OpenAI: GPT-5.6 Luna Pro vs OpenAI GPT-5.3-Codex: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing OpenAI: GPT-5.6 Luna Pro (openai/gpt-5.6-luna-pro) vs OpenAI GPT-5.3-Codex (gpt-5.3-codex). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
OpenAI: GPT-5.6 Luna Pro (openai/gpt-5.6-luna-pro) 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-5.3-Codex (gpt-5.3-codex) 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-5.6 Luna Pro (API ID: openai/gpt-5.6-luna-pro) vs OpenAI GPT-5.3-Codex (API ID: gpt-5.3-codex), OpenAI: GPT-5.6 Luna Pro offers lower standard input pricing at $0.2/1M tokens ($1.2/1M output), while OpenAI: GPT-5.6 Luna Pro leads in cached prefix economics at $0.1/1M tokens (50% discount). OpenAI GPT-5.3-Codex achieves a 30ms faster P90 time-to-first-token latency (250ms 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 | OpenAI: GPT-5.6 Luna Pro | OpenAI GPT-5.3-Codex | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | openai/gpt-5.6-luna-pro | gpt-5.3-codex | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.2 / $1.2 | $1.75 / $14 | OpenAI: GPT-5.6 Luna Pro |
| Cache Read Price (per 1M) | $0.1/1M (50% Off) | $0.875/1M (50% Off) | OpenAI: GPT-5.6 Luna Pro |
| Context Window / Max Output | 1025K In / 125K Out | 1000K In / 128K Out | OpenAI GPT-5.3-Codex |
| P90 First-Token / Edge Latency | 280ms | 250ms | OpenAI GPT-5.3-Codex (-30ms) |
GPT-5.6 Luna Pro is the same underlying model as [GPT-5.6 Luna](https://openrouter.ai/openai/gpt-5.6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses o
Dedicated agentic software engineering model tuned for multi-hour terminal and IDE sessions.
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-5.6 Luna Pro to OpenAI GPT-5.3-Codex
Dedicated agentic software engineering model tuned for multi-hour terminal and IDE sessions. Verified P90 latency of 250ms.