Skip to content
Sir CompareComparisons with evidenceAsk Sir CompareAsk
English · USD

Product

GPT-6 Luna: specs, API pricing and data

Updated

OpenAI gpt-6-luna — drawn card, not a photograph of the product

OpenAIAI Models & LLMs

Context window
1.05M tokens
Maximum output
128k tokens
Input cost per 1M tokens
$0.10
Output cost per 1M tokens
$0.50
Knowledge cutoff
May 2026

You use it and pay per use through the vendor's API, per million tokens: there is no shop. The list prices are in the data sheet below.

Data sheet · GPT-6 Luna

Every figure is quoted from the vendor's official page, with the date we read it. If a row is missing, the source does not state it and we do not estimate it.

Memory and answer length

Context window
1.05M tokensRank 1 of 21
What it means and the source

How much text the model keeps in view in a single request, question and answer included. It matters for long documents and whole code projects. A token is a fragment of a word.

developers.openai.comOpens the source in a new tab Oct 23, 2026
Maximum output
128k tokensRank 3 of 16
What it means and the source

The longest answer it can write in one go: useful for reports, long code or translations of whole documents.

developers.openai.comOpens the source in a new tab Oct 23, 2026

API prices

Input cost per 1M tokens
$0.10Rank 1 of 21
What it means and the source

What it costs to have the model read a million tokens (your question, the documents, the code). It is the official list price, before discounts.

developers.openai.comOpens the source in a new tab Oct 23, 2026
Cached input cost per 1M tokens
$0.01Rank 2 of 20
What it means and the source

The reduced price when part of the request is identical to one sent recently, for example the same instructions or the same document: the vendor keeps it in memory and charges less for it.

developers.openai.comOpens the source in a new tab Oct 23, 2026
Output cost per 1M tokens
$0.50Rank 1 of 21
What it means and the source

What a million tokens written by the model cost. It usually costs more than the input and is the figure to watch when answers are long.

developers.openai.comOpens the source in a new tab Oct 23, 2026

Knowledge and abilities

Knowledge cutoff
May 2026Rank 5 of 9
What it means and the source

The month up to which the model's knowledge reaches. For more recent facts it needs web search or your documents.

developers.openai.comOpens the source in a new tab Oct 23, 2026
Reads images
Yes13 models out of 23
What it means and the source

The model can take images (photos, screenshots, charts) as well as text.

developers.openai.comOpens the source in a new tab Oct 23, 2026
Calls tools and functions
Yes12 models out of 23
What it means and the source

The model can call functions and tools (search, calculations, other applications) to take actions and not only write text: it matters for assistants and agents.

developers.openai.comOpens the source in a new tab Oct 23, 2026

Questions and answers

GPT-6 Luna: how much does it cost through the API?

The official list price is $0.10 per 1M input tokens and $0.50 per 1M output tokens.

GPT-6 Luna: how much text can it read at once?

The context window is 1.05M tokens. It can write answers of up to 128k tokens.

GPT-6 Luna: how recent is its knowledge?

Its knowledge reaches May 2026. For more recent facts it needs web search or your documents.

The short version

On OpenAI GPT-6 Luna the figure that actually matters is Context window: 1.05M. I took that figure from OpenAI – Models. Among the 21 I checked, none does better. The other figure to look at is Output cost per 1M tokens: 0.5.

The numbers on OpenAI GPT-6 Luna

I put them in order of importance, with the value and the standing against the others I checked.

Context window: 1.05M. That is the best value among the 21 I compared.

Output cost per 1M tokens: 0.5. That is the best value among the 21 I compared.

Input cost per 1M tokens: 0.1. That is the best value among the 21 I compared.

Cached input cost per 1M tokens (USD): 0.01. Rank 18 of the 20 I compared.

Calls tools and functions: 1. That is the best value among the 12 I compared.

Knowledge cutoff: May 18, 2026. Rank 5 of the 9 I compared.

Subject illustration: Illustration of an application (illustrative image, not a photo of the product)
Who it is for

Take it if Context window is your priority: 1.05M, and none of the ones I checked does better.

It suits you if you are after Output cost per 1M tokens: 0.5.

Explore related coverage

Sources

Ask Sir Compare:Explain these numbers to me

Reviews and tests

OpenAI GPT-6 Luna

Reviews and tests · OpenAI GPT-6 Luna

Reviews are not available yet.

What changed

  • Page updated
  • Page updated

How I put products in order

Your assistant

Open full page →