OpenAI Previews Its Next-Gen GPT-5.6: Sol, Terra, and Luna

OpenAI has announced its next-generation GPT-5.6 series in a limited preview: flagship Sol, the balanced Terra for everyday work, and the fast, affordable Luna. In the new naming, the number marks the generation while the names mark durable capability tiers — intelligence, speed, and cost.

In brief

• Three tiers: Sol is the flagship; Terra matches GPT-5.5 performance at 2x cheaper; Luna is strong at the lowest cost. Pricing (per 1M tokens): Sol $5/$30, Terra $2.50/$15, Luna $1/$6.
• New modes: a "max reasoning" effort for deeper thinking, and an ultra mode that goes beyond a single agent by using subagents to speed up complex work.
• Capability: a new state of the art on Terminal-Bench 2.1 for coding; on GeneBench it beats GPT-5.5 in biology using fewer tokens; it's OpenAI's most capable model yet for cybersecurity.
• Phased launch: because of the jump in cyber capability, it starts with trusted partners only; OpenAI previewed its plans to the U.S. government and is starting narrow at their request — with broad access on ChatGPT/Codex/API to follow soon.

Our take

The practical part for you: you no longer have to run the same expensive model for every task. That's what the Sol/Terra/Luna split is for — send routine work (summaries, drafts, simple code) to Luna or Terra, and only reach for Sol on genuinely hard problems. Matching the tier to the task can quietly halve your monthly AI bill. One caveat: the model is opening through a narrow door for now, so access may not reach everyone at once.

Kaynak: OpenAI