GPT-6 Luna
OpenAI · Released Sep 2026
Conditional
GPT-6 Luna is OpenAI's new budget model and the cheapest way into GPT-6, at half GPT-5.6 Luna's input rate, with a 1.05M-token context and text and image input. Conditional because every published result is OpenAI's own and prompts over 272K input tokens bill at higher rates. GPT-5.6 Luna stays on the price list with no deprecation notice, so migration is optional. Right for teams running high-volume, everyday API work at scale.
Is it right for you?
Good for
- High-volume, low-cost calls: $0.10 input and $0.50 output per 1M tokens, cached input $0.01, batch $0.05/$0.25
- Budget coding agents: OpenAI reports 66.6% on DeepSWE v1.1 at max effort, against 68.8% for GPT-6 Sol
- Long documents on a small budget: a 1,050,000-token context window and up to 128,000 output tokens
- Trying it without an API key: Free and Go users get it in the ChatGPT desktop app
Not good for
- Long prompts budgeted off the headline rate: over 272K input tokens it bills $0.20 input and $0.75 output per 1M
- Decisions that need independent benchmarks: every published result is OpenAI's own
Pricing
Input
$0.10 / 1M tokens
Output
$0.50 / 1M tokens
Context
1.05M ctx; over 272K $0.20/$0.75; cache $0.01
Benchmarks
| Benchmark | Score | Source |
|---|---|---|
| DeepSWE v1.1, max effort (OpenAI-reported) | 66.6% | Source |
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Sources
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