The lineup features Sol as the flagship model, Terra at a reduced cost, and Luna at the lowest price point, with broad availability expected in the coming weeks.
OpenAI has initiated a limited preview of the GPT-5.6 series, comprising three models with distinct cost and performance profiles. The release includes Sol, described as the company's flagship model; Terra, aimed at everyday tasks with performance comparable to GPT-5.5 at half the cost; and Luna, positioned as the fastest and most affordable option in the lineup.
According to the company, all three models should become widely available in the coming weeks. The current preview phase restricts access to a select group of trusted partners, a move that was communicated to the United States government.
The measure is part of OpenAI's ongoing engagement with the U.S. government. The company states it presented its plans and the models' capabilities prior to the public announcement, and the limited release format reportedly came at the request of government officials.
The strategy of launching three models with different pricing and capability tiers reflects OpenAI's effort to cater to a broad user base, ranging from applications requiring high performance to more cost-sensitive use cases. The company reiterated its commitment to broad access to the technology, although the controlled rollout indicates caution in the initial distribution.
The GPT-5.6 series features three models: Sol, the flagship model; Terra, which offers performance comparable to GPT-5.5 at half the cost; and Luna, the fastest and most affordable option.
The limited preview restricts access to a select group of trusted partners at the request of U.S. government officials. OpenAI presented the models' capabilities to the government prior to the public announcement as part of their ongoing engagement.
OpenAI states that all three GPT-5.6 models (Sol, Terra, and Luna) are expected to become widely available to the public in the coming weeks.