OpenAI Touts GPT-5.6 Sol Upgrades, Opens GPT-5.6 Luna to Free ChatGPT Users

OpenAI has published an announcement signaling two changes to its ChatGPT model lineup: improvements to the GPT-5.6 ‘Sol’ variant, and wider availability of GPT-5.6 ‘Luna’ to users on the free tier. The move fits the company’s established pattern of iterating on model variants and gradually pushing newer capabilities down to non-paying users.

Note for editorial review: the provided source contained only this headline with no accompanying article body. The specifics — what the Sol improvements consist of, any performance or safety benchmarks, the scope and timeline of the expanded Luna free-tier access, and rate or usage limits — are not present in the supplied text and cannot be summarized without pulling the actual article. Recommend fetching the full page at the OpenAI URL before publishing.