OpenAI · GPT-6
GPT-6 Luna
OpenAI's fastest, cheapest current model for focused, high-volume tasks such as summarising, extracting and lightweight coding, released 22 September 2026 as the successor to GPT-5.6 Luna. Free and Go users can try it in the ChatGPT desktop app; GPT-5.6 Luna remains available during the rollout.
Start here
- What this helps you do
- Decide whether GPT-6 Luna is the right model for a job you have, or one to leave alone.
- What you leave with
- A plain read of what GPT-6 Luna is for, what to avoid giving it, and the facts behind that.
- What to check before trusting it
- Released 22 September 2026, so real-world track record is minimal at review time.
A reasonable default for high-volume, low-stakes work once you have checked it against GPT-5.6 Luna on your own task; the price drop is real, but confirm quality holds before routing volume through it.
Use it for
- Summarisation and extraction at volume
- Focused, repetitive coding tasks
- Quick everyday work where Sol's extra reasoning is not needed
Do not reach for it on genuinely hard multi-step reasoning or long-horizon agentic work; that is what Sol and Astra are for.
Effort without the jargon
OpenAI documents Luna's reasoning effort as going up to Max but not Ultra; use higher effort only for tasks that need more than a quick pass, and reach for Sol once that is not enough.
Advanced recordCost, limits, privacy and operations
This is the cheap, high-volume option; confirm it holds quality on your own summarisation or extraction task before routing real volume through it.
- API cost
- Officially disclosedOpenAI API price: $0.10 per million input tokens, $0.01 cached input and $0.50 per million output tokens.
- Context window
- Officially disclosed1,050,000 tokens
- Maximum output
- Officially disclosed128,000 tokens
- Knowledge cutoff
- Officially disclosed18 May 2026
- Recorded inputs
- Not enumerated in cited record
- Recorded output
- Text
Data handling is a product decision
Depends on surfaceRetention and training rules belong to the ChatGPT plan, API account and workspace, not the model name alone; the cited model page does not restate them.
Operational constraints
- Released 22 September 2026, so real-world track record is minimal at review time.
- Reasoning effort goes up to Max but not Ultra, per OpenAI's own product documentation.
- GPT-5.6 Luna remains available during the rollout, so this is not a forced migration.
- The cited model page does not enumerate input modalities beyond text; treat image input as unconfirmed until checked against a live request.
Record details
- Evidence readiness
- informational
- Guidance confidence
- moderate
- Evidence revision
- gpt-6-luna@v1
Unknown means the cited official record does not disclose a safe value. It is not an estimate. Prices are provider list prices in USD where stated and can change before this record's review date.
Keep the evidence separate
OpenAI describes GPT-6 Luna as its most efficient model for focused, high-volume tasks including summarisation, extraction and focused coding, built on the advances behind GPT-6 Astra brought into a faster, more affordable model.
No sufficiently useful independent note has been added yet. That absence is not filled with our guess.
No Human Bit result is claimed; use this as evaluation guidance only.
Not scheduled
No Human Bit result is claimed for this model yet.