GPT-5.6 Luna vs Gemini Flash
Both are built for volume, and both got materially cheaper in 2026 — OpenAI cut Luna's price by 80% in July, Google shipped 3.7 Flash in August. Luna inherits the GPT-5.6 context window and OpenAI's tooling; Flash is the stronger agent runner. Benchmark them on your own traffic, because at this price tier the differences are workload-specific.
| GPT-5.6 Luna | Gemini Flash | |
|---|---|---|
| Provider | OpenAI | |
| Current release | GPT-5.6 Luna | 3.7 Flash |
| Tier | Fast & cheap | Fast & cheap |
| Context | 1M | 1M |
| Cost | Low cost | Low cost |
| Modalities | text, vision | text, vision, audio |
| Open weights | No | No |
Cost is a tier, not a quote — providers change prices often. Check OpenAI and Google before you commit. Last updated 2026-08-14.
Which one to pick
GPT-5.6 LunaOpenAI
Classification, routing, and extraction at volume
Reach for it when- You are standardising on the GPT-5.6 ladder
- Routing and classification inside an OpenAI stack
Gemini FlashGoogle · 3.7 Flash
High-volume agent loops and prototyping — cheap enough to run constantly
Reach for it when- Agent loops that call tools repeatedly
- Squeezing the lowest cost per useful completion