GPT-6 Luna
Released
GPT-6 Luna is an AI model released by OpenAI on Tuesday, Sep 22 2026, the same day as GPT-6 Sol. It has a 1.05M token context windowHow much information the model can work with in one request, measured in tokens — pieces of words or other data. This includes your question, attachments, conversation and reply. Limits can vary by model variant and provider.. Benchmark results (shown below) cover BullshitBench v2, DeepSWE 1.1, Next.js Evals, Supabase Evals, Terminal-Bench 4.0, ARC-AGI-2, and 1 more.
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API pricing
- InputWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
- $0.10
- Cached inputA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again.
- $0.01
- Cache writeA one-off charge for storing text so later requests can reuse it at the cheaper cached rate.
- $0.125
- OutputWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one.
- $0.50
- InputWhat you pay for everything you send the model — your question, plus any documents or earlier conversation you include with it.
- $0.20
- Cached inputA reduced rate for text you send over and over. If every request starts with the same instructions or the same document, the provider keeps a copy ready and charges less to read it again.
- $0.02
- Cache writeA one-off charge for storing text so later requests can reuse it at the cheaper cached rate.
- $0.25
- OutputWhat you pay for the text the model writes back. It is normally the dearer half: producing an answer costs more than reading one.
- $0.75
- Reasoning or thinking is supported.
- OpenAI also publishes a Fast mode for this model at exactly twice the standard rate in every column — $0.20 per million input tokens and $1.00 per million output at short context.
Available from
| OpenAI | — | flex | $0.05 | $0.25 | 1M |
|---|---|---|---|---|---|
| OpenAI | — | — | $0.10 | $0.50 | 1M |
| Amazon Bedrock | global | — | $0.10 | $0.50 | 1M |
| Azure | — | — | $0.10 | $0.50 | 1M |
| Amazon Bedrock | us-east-1 | — | $0.11 | $0.55 | 1M |
| Azure | eu | — | $0.11 | $0.55 | 1M |
| Azure | us | — | $0.11 | $0.55 | 1M |
| OpenAI | — | fast | $0.20 | $1.00 | 1M |
Benchmarks
Coding
Terminal & CLI
Reasoning & science
Robustness
Community preference
Source: Terminal-Bench, retrieved 12 October 2026 · Source: BenchLM, retrieved 28 September 2026. Other sources are identified on the linked benchmark pages.
Compare GPT-6 Luna with
Suggested comparisons
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GPT-6 Luna was introduced in September 2026 as the smaller, efficiency-focused model in OpenAI's GPT-6 family, alongside Sol. OpenAI positioned it for frequent, focused tasks and offered it through the API and selected ChatGPT experiences. At launch, Free and Go users could access Luna in the desktop app, while access through other plans and interfaces followed the announced product rules.
The API documented text and image inputs, text output and a 1,050,000-token context window, with adjustable reasoning effort. Its smaller-tier role did not imply a short context limit or downloadable weights. The release emphasized lower operating cost for repeated work; performance and latency still depended on the chosen reasoning setting and surrounding application.
Frequently asked questions
GPT-6 Luna was released by OpenAI on Tuesday, Sep 22 2026.