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GPT-6 Luna

OpenAI's fast, cheap model for chat, sorting things into groups and light tasks.

Last updated October 16, 2026.

Costs here use the prices AI companies charge software developers, so they show relative cost, not your monthly bill. See what ChatGPT, Claude and Gemini charge you.

Made by OpenAI, the company behind ChatGPT. Everyday and cheap.

What it costs

1,000-word essay: under 1 cent
100 chat messages: $0.13 (about 13 cents)
50-page PDF summary: under 1 cent

Based on list prices and the assumptions on How we work. Your real cost will differ.

At a glance

Smartness: ★★★☆☆ (3 of 5) (our banding of the Artificial Analysis score, where available)
Reads at once: about 1,580 pages (rule of thumb)
Understands: files, pictures, text
Free to download and run yourself: No
Free to use: Not free for developers. Free app plans

App plans and prices for ChatGPT: see plans.

Best for

chatsorting and labelinglight tasks

Watch out for

Costs more for very long inputs.

Appears in

Compare

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Frequently asked

How much does GPT-6 Luna cost to use?
A 1,000-word essay costs about under 1 cent; summarizing a 50-page PDF about under 1 cent. These are developer (API) prices, not an app subscription.

What is GPT-6 Luna best for?
OpenAI's fast, cheap model for chat, sorting things into groups and light tasks.

How much can GPT-6 Luna read at once?
About 1,580 pages (a rule of thumb: 1,050,000 tokens at roughly 500 words a page).

Can I download GPT-6 Luna for free?
No. It is only available through the maker or other paid services.

Under the hood

Maker	OpenAI
Price per 1M input tokens	$0.10 (changes with input length or day of week)
Price per 1M output tokens	$0.50
Context size	1.05M tokens (1,050,000)
Artificial Analysis Intelligence Index	38.1 (source, via OpenRouter)
Open weights	No
Speed	Not measured yet
Listed	2026-09-22

Maker's description (technical)

GPT-6 Luna is the fast, cost-efficient model in OpenAI's GPT-6 series, positioned below GPT-6 Sol. It is suited for high-volume and latency-sensitive workloads such as chat, classification, and lightweight agentic...

View on OpenRouter. Our verdict above is editorial, not benchmarked by us.