Gemini 3.6 Flash vs GPT-5.6 Luna
Facts only. This page does not pick a winner. For a picked winner, see the use case comparison on Tools.
| Gemini 3.6 Flash | GPT-5.6 Luna | |
|---|---|---|
| API model IDs | gemini-3.6-flash | gpt-5.6-luna |
| Context window | 1,048,576 | 1,050,000 |
| Lifecycle | active | active |
| License | proprietary | proprietary |
| Trains on API data | No | No |
| Zero data retention | on-request | on-request |
| Input per 1M tokens | $0.75 (verified 2026-09-08) | $0.2 (verified 2026-09-08) |
Frequently asked questions
- Which has the larger context window, Gemini 3.6 Flash or GPT-5.6 Luna?
- Gemini 3.6 Flash holds 1,048,576 tokens and GPT-5.6 Luna holds 1,050,000. GPT-5.6 Luna holds more. The context window counts the prompt, any attached files, and the reply together.
- Which is cheaper, Gemini 3.6 Flash or GPT-5.6 Luna?
- Per million input tokens, Gemini 3.6 Flash was $0.75 (verified 2026-09-08) and GPT-5.6 Luna was $0.2 (verified 2026-09-08). GPT-5.6 Luna is cheaper per input token. Output tokens cost $3.75 and $1.2 respectively, and output volume usually decides the bill.
- Does Gemini 3.6 Flash or GPT-5.6 Luna train on API data?
- Gemini 3.6 Flash does not train on API data by default, and GPT-5.6 Luna does not train on API data by default. Zero data retention is on-request for Gemini 3.6 Flash and on-request for GPT-5.6 Luna. Verified 2026-09-08 and 2026-09-08 against the providers' own documentation.
- Is Gemini 3.6 Flash or GPT-5.6 Luna being retired?
- Gemini 3.6 Flash is active. GPT-5.6 Luna is active. Lifecycle checked 2026-09-08 and 2026-09-08. Pin a dated snapshot ID rather than an alias if a retirement would break you.