OpenAI

GPT-5.6 Luna

The fastest, most affordable GPT-5.6 tier for high-volume drafting, summarization, and routine automation where latency and cost dominate.

ActiveReleased July 9, 2026Knowledge cutoff February 16, 2026Available from 5 providers
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: OpenAI models, OpenAI pricing, Prompt caching (1,024 minimum, 30m TTL)

Price per 1M tokens
$0.2 in / $1.2 out
Context window1,050,000
Max output128,000
Cache read$0.02 / M
Min cache prefix1,024 tokens
Cache lifetime30 min
Batch discount-50%
Input
  • Text
  • Image
Output
  • Text
Priced across5 providers

Pricing

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

Billing legRateBatch
Input$0.2 / M$0.1 / M
Output$1.2 / M$0.6 / M
Cache read$0.02 / M$0.01 / M
Cache write$0.25 / M$0.125 / M

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
$112
at current list prices
Fresh input$40.00
Cached input$0.00
Output incl. thinking$72.00
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Compare providers

The same model, priced across every platform that serves it. Lowest combined in/out rate is flagged.

PlatformRegionInput / MOutput / MCache read / MBatchAccess
OpenAILowest
-$0.2$1.2$0.02✓First-party API
Cursor
-$0.2$1.2$0.02-Direct
Azure AI Foundry
-$0.2$1.2$0.02-Direct
AWS Bedrock
$0.22$1.32$0.022-Direct
Azure AI Foundry · Data zone
-$0.22$1.32$0.022-Direct

Some hosts price by region. Shown rates match the selected region.

Price history

Has this model gotten cheaper or more expensive?

EffectiveInput / OutputStatus
July 10, 2026 – July 30, 2026$1 / $6past
July 30, 2026 – August 23, 2026$0.2 / $1.2past
August 23, 2026 – September 23, 2026$0.2 / $1.2past
September 23, 2026$0.2 / $1.2current

More from OpenAI

Other models from the same provider.

GPT-6.1 Sol
openai/gpt-6.1-sol
$2 / $10 in / out per 1M
GPT-6 Sol
openai/gpt-6-sol
$2 / $10 in / out per 1M
GPT-6 Luna
openai/gpt-6-luna
$0.1 / $0.5 in / out per 1M
GPT-6 Astra
openai/gpt-6-astra
$10 / $50 in / out per 1M
GPT-5.6 Sol
openai/gpt-5.6-sol
$4 / $20 in / out per 1M
GPT-5.6 Terra
openai/gpt-5.6-terra
$2 / $12 in / out per 1M

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Rates are generated from SuperPenguin's live pricing catalog.