OpenAI moves GPT-5.6 to general availability across ChatGPT, API and Codex

OpenAI began publicly rolling out GPT-5.6, its three-tier model family of Sol, Terra and Luna, across ChatGPT, the API and Codex on July 9, 2026, moving the release from a limited preview to general availability.

The family had been in preview with a small set of partners since around June 26 and cleared additional government testing through the U.S. Department of Commerce’s Center for AI Standards and Innovation before the wider launch, OpenAI said in its announcement.

Pricing splits the family by cost and capability. Sol, the flagship reasoning and agentic model, runs $5 per million input tokens and $30 per million output tokens. Terra delivers roughly GPT-5.5-level performance at about half the cost, at $2.50 in and $15 out. Luna, the fastest and cheapest tier, costs $1 in and $6 out.

Access tracks the subscription. Free and Go users on ChatGPT get Terra; Plus, Pro, Business and Enterprise users can pick any of the three, and Pro and Enterprise accounts add a ‘Sol Pro’ setting for the highest-effort tasks. Developers can call all three tiers directly through the OpenAI API.

The tiered structure reads as a response to price pressure from rivals, letting customers trade accuracy for cost rather than defaulting to the most expensive model. OpenAI’s performance framing — that Terra roughly matches the prior GPT-5.5 at half the price — is the company’s own and has not been independently benchmarked.

For now the rollout is staged rather than instant, and OpenAI has not said how quickly every account and region will see all three tiers.