SIDE BY SIDE
GPT-5.6 Luna vs GPT-6 Luna
Both are GPT models. GPT-6 Luna was added to OpenRouter on 2026-09-22, GPT-5.6 Luna on 2026-07-09.
| Field | GPT-5.6 Luna | GPT-6 Luna |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Family | GPT | GPT |
| Province | Snow Country | Snow Country |
| Context window | 1.05M tokens | 1.05M tokens |
| Maximum output | 128K tokens | 128K tokens |
| Input / 1M tokens | $0.200 | $0.100 |
| Output / 1M tokens | $1.20 | $0.500 |
| Accepts | text, files, images | text, files, images |
| Produces | text | text |
| Reasoning | Yes | Yes |
| Tool use | Yes | Yes |
| Added to OpenRouter | 2026-07-09 | 2026-09-22 |
| Model ID | openai/gpt-5.6-luna | openai/gpt-6-luna |
Questions and answers
Which is cheaper, GPT-5.6 Luna or GPT-6 Luna?
GPT-6 Luna costs less for both input ($0.100 vs $0.200) and output ($0.500 vs $1.20) per million tokens. On input, GPT-6 Luna is 50% cheaper.
Which has the larger context window?
Both have a 1.05M-token context window.
What can one do that the other cannot?
Nothing among reasoning, tool use and image input: both support reasoning, tool use and image input.
Answers are computed from the 2026-10-24 catalog snapshot.