# OpenAI previews GPT-5.6, including a cheaper Terra model

By Steven Van · 2026-06-27

Sol, Terra and Luna target coding, computer use and research, with Terra roughly matching GPT-5.5 at half the cost.

OpenAI is running a limited preview of the GPT-5.6 model family: **Sol**, the flagship model, **Terra**, a balanced model with performance competitive with GPT-5.5 at roughly half the cost, and **Luna**, a fast, low-cost model. The family targets software engineering, computer use, knowledge work, research and cybersecurity, and adds a new max reasoning effort setting.

Sol ships with what OpenAI calls its most robust safety stack to date, with strengthened protections against higher-risk activity, sensitive cyber requests and repeated misuse. The preview is available via the API and in [Codex](<https://openai.com/index/previewing-gpt-5-6-sol/>), and can be used through [ChatGPT](<https://creatorstoolbox.com/tools/chatgpt>).

[![](<https://creatorstoolbox.com/images/chatgpt-thumbnail.png>)](<https://openai.com/index/previewing-gpt-5-6-sol/>)

![ChatGPT](<https://www.google.com/s2/favicons?domain=chatgpt.com&sz=128>)

ChatGPT

AI assistant by OpenAI — chat, write, code, analyse data, generate images, and browse the web, powered by the GPT-5.6 family.

[View ChatGPT →](<https://creatorstoolbox.com/tools/chatgpt>)

Sources

[Original source](<https://openai.com/index/previewing-gpt-5-6-sol/>)

[Read OpenAI previews GPT-5.6, including a cheaper Terra model on Creators Toolbox](<https://creatorstoolbox.com/blog/chatgpt-previewing-gpt-5-6-sol>)

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Canonical source: https://creatorstoolbox.com/blog/chatgpt-previewing-gpt-5-6-sol