OpenAI GPT-5.6 launches publicly as a three-tier model family after US government review

GPT-5.6 was released publicly on July 9, 2026, as a family of models that comes in three distinct variants, ranked from least to most capable: Luna, Terra, and Sol. OpenAI described the launch, previewed in its introducing GPT-5.6 Sol announcement, as bringing its new flagship, Sol, alongside Terra, a balanced model for everyday work, and ... Read more