OpenAI unveils GPT 5.6 family of AI models, but you can’t use them yet: Here is why
Follow UsOpenAI has introduced the GPT 5.6 series, which includes three AI models: Sol, Luna and Terra.
According to OpenAI, GPT 5.6 Sol is its "most capable model yet for cybersecurity."
OpneAI says it has developed Sol, Terra and Luna with its "most robust safeguards to date."
OpenAI has introduced the GPT 5.6 series, which includes three AI models: Sol, Luna and Terra. GPT 5.6 Sol is the company’s most powerful model yet, Terra is a balanced model for everyday tasks, and Luna is a faster and more affordable option. The company says it has developed GPT 5.6 Sol, Terra and Luna with its “most robust safeguards to date.” Unfortunately, general users cannot access these models yet. Instead of a public rollout, OpenAI is starting with a limited preview for a small group of trusted partners. According to the company, this decision was made because the US government requested an early preview before a wider launch. OpenAI says it still plans to make the GPT 5.6 family available through ChatGPT, the API and Codex in the coming weeks.
SurveyOpenAI GPT 5.6 series: Capabilities
OpenAI says GPT 5.6 Sol is its “strongest model” so far. The company also claims that Sol is its “most capable model yet for cybersecurity.” It is said to offer improved agentic capabilities in coding, biology, and cybersecurity tasks. OpenAI claims the GPT 5.6 Sol AI model is better at helping people find and fix vulnerabilities without crossing its internal safety limits.
The company is also introducing a new ‘max’ reasoning option, which allows Sol to spend more time solving difficult problems. Also, there is an ‘ultra’ mode that uses multiple AI sub-agents to complete complex tasks faster.
Meanwhile, Terra offers performance similar to GPT 5.5 at half the price, and Luna is designed as the fastest and most affordable model in the new family.
Also read: OpenAI says AI agents are already transforming how its employees work
Good new first: Sol is a smart, efficient, and a significant step forward. It is the same price as GPT-5.5. Also launching in the GPT-5.6 family is Terra, with 5.5-level performance at half the price.
— Sam Altman (@sama) June 26, 2026
Bad news: at the request of the US government, it is launching today in…
Why OpenAI GPT 5.6 models are not available to the public
OpenAI confirmed that GPT 5.6 models are launching only as a limited preview. The company said it shared the models with the US government before release and, “at their request, we are starting with a limited preview for a small group of trusted partners before releasing more broadly.”
CEO Sam Altman also posted about the decision on X (formerly Twitter). Calling it the “bad news,” he wrote, “At the request of the US government, it is launching today in limited preview instead of the open access launch we were planning on.” “We are working with the government to get to general availability as fast as we can.”
Altman added that the gradual rollouts are a “quite reasonable” approach for increasingly capable AI systems, but said this “isn’t quite the process that we think is optimal.” He said the company is working with the government to create a transparent and reliable process so future AI models can reach users more quickly.
OpenAI also said it does not want government previews to become the “long-term default.” “It keeps the best tools from users, developers, enterprises, cyber defenders, and global partners who need them. We are taking this short-term step because we believe it is the strongest path to broader availability in the coming weeks, while we work with the Administration to develop the cyber Executive Order framework and a repeatable process for future model releases.”
