OpenAI

GPT-6 Luna

An efficient reasoning model for focused, high-volume tasks, with text and image input, a 1.05M-token context window, and adjustable reasoning effort.

ActiveReleased September 22, 2026Knowledge cutoff May 18, 2026
Tool callingCan invoke external tools and APIs (function calling) mid-response.Structured outputCan return JSON or schema-constrained responses instead of free text.ReasoningUses extended thinking / chain-of-thought for harder multi-step problems.Effort controlLets you dial thinking depth (low / medium / high) to trade cost for quality.Fine-tuningSupports training a custom variant on your own data (vendor fine-tune API or self-hosted open weights).

Source: Official model specifications and supported features, API release date: September 22, 2026, 1024-token cache minimum and default 30-minute minimum lifetime, Reasoning token billing, Pricing, context tiers, and service tiers

Price per 1M tokens
$0.1 in / $0.5 out
Context window1,050,000
Max output128,000
Cache read$0.01 / M
Min cache prefix1,024 tokens
Cache lifetime30 min
Batch discount-50%
Input
  • Text
  • Image
Output
  • Text

Pricing

Every billing leg from the live catalog, in USD per 1M tokens.

Billing legStandardLong contextBatch
Input$0.1 / M$0.2 / M$0.05 / M
Output$0.5 / M$0.75 / M$0.25 / M
Cache read$0.01 / M$0.02 / M$0.005 / M
Cache write$0.125 / M$0.25 / M$0.0625 / M

Long-context rates apply above 272,000 input tokens.

Cost calculator

Billing-grade math over the rate card above, including the thinking tokens most estimates miss.

Hidden reasoning tokens bill as output. 1.0x = thinking off. Medium-effort reasoning typically lands near 3x; heavy reasoning runs 6x to 8x. Set it to match your workload.

Estimated monthly cost
$50.00
at current list prices
Fresh input$20.00
Cached input$0.00
Output incl. thinking$30.00
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Provider

Where this model runs, and what it charges.

PlatformInput / MOutput / MCache read / MBatchAccess
OpenAI
$0.1$0.5$0.01✓First-party API

Price history

Has this model gotten cheaper or more expensive?

No changePriced at $0.1 / $0.5 per 1M since September 23, 2026.

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GPT-5.6 Luna
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GPT-5.5
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Rates are generated from SuperPenguin's live pricing catalog.