Audience

Developers and product teams that need a fast model for everyday AI features, coding support, API workflows, and scalable assistant experiences

About GPT-5.6 Luna

GPT-5.6 Luna is the fast and affordable model in OpenAI’s GPT-5.6 series, built to bring strong capability to users and developers who need practical intelligence with lower overhead. In the new GPT-5.6 naming system, the number identifies the model generation, while Sol, Terra, and Luna identify durable capability tiers that can advance on their own cadence, giving people and developers clearer choices across intelligence, speed, and cost. Luna sits alongside Sol, the flagship model, and Terra, the balanced model for everyday work, as part of a family designed for broader access to next-generation AI. During the limited preview, GPT-5.6 models are initially available through the API and Codex to a select group of trusted partners and organizations, with plans for broader availability in ChatGPT, Codex, and the API. OpenAI developed GPT-5.6 Sol, Terra, and Luna with its most robust safeguards to date, with configurations matched to each model’s capabilities.

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Pricing

Starting Price:
$0.20 per 1M tokens (input)
Pricing Details:
$0.20 input / $1.20 output per 1 million tokens

Integrations

API:
Yes, GPT-5.6 Luna offers API access
See Integrations

Ratings/Reviews - 1 User Review

Overall 5.0 / 5
ease 5.0 / 5
features 4.0 / 5
design 5.0 / 5
More Reviews Write a Review

Company Information

OpenAI
Founded: 2015
United States
openai.com

Videos and Screen Captures

GPT-5.6 Luna Screenshot 1
GPT-5.6 Luna Screenshot 1 GPT-5.6 Luna Screenshot 2
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Product Details

Platforms Supported
Cloud
Training
Documentation
Support
Online

GPT-5.6 Luna Frequently Asked Questions

Q: What kinds of users and organization types does GPT-5.6 Luna work with?
Q: What languages does GPT-5.6 Luna support in their product?
Q: What kind of support options does GPT-5.6 Luna offer?
Q: What other applications or services does GPT-5.6 Luna integrate with?
Q: Does GPT-5.6 Luna have an API?
Q: What type of training does GPT-5.6 Luna provide?
Q: How much does GPT-5.6 Luna cost?

GPT-5.6 Luna Product Features

GPT-5.6 Luna Verified User Reviews

Write a Review
  • A GPT-5.6 Luna User
    Engineer
    Used the software for: Less than 6 months
    Frequency of Use: Daily
    User Role: User
    Company Size: 500 - 999
    Design
    Ease
    Features
    Pricing
    Probability You Would Recommend?
    1 2 3 4 5 6 7 8 9 10

    "Great fast model"

    Posted 2026-07-09

    Pros: GPT-5.6 Luna is the one I would use when speed and cost matter most. As a developer, I can see it being really useful for lightweight coding help, quick explanations, small refactors, simple scripts, test generation, issue triage, and agent steps that do not need the most expensive model in the stack.

    I also like Luna for multi-agent systems where a lot of small tasks need to run in parallel. OpenAI describes Luna as the fastest and most cost-efficient GPT-5.6 model, and that is exactly the kind of model developers need for high-volume workflows.

    Cons: Luna is not the model I would choose for the hardest reasoning tasks. If I were debugging a complicated distributed system, planning a major architecture change, or running a long autonomous coding agent, I would probably step up to Terra or Sol.

    It also depends heavily on good task routing. Luna can be extremely valuable when used for the right jobs, but expecting it to perform like the flagship model on every problem would be the wrong approach.

    Overall: Five stars from me. GPT-5.6 Luna looks like a great fit for fast, affordable developer workflows where you need lots of useful AI assistance without paying flagship-model prices. It is the model I would use to make AI coding support feel always-on instead of expensive and occasional.

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