OpenAI broadly releases GPT-5.6 after government-gated preview
Confirmed
Importance: major (4 of 5)The takeaway
GPT-5.6, a three-tier model family (Sol flagship, Terra mid, Luna fast/cheap), was broadly released on July 9, 2026 after a limited, government-approved preview from June 26.
Status
- Claim
Confirmed
- Our reporting
- High confidence
- Importance
- Major (4 of 5)
- Last verified
- 29 September 2026
Your AI and this story
- GPT-6 Astra70 days after its cutoff
- Claude Opus 5.59 days after its cutoff
- Gemini 4 Hydrogen100 days after its cutoff
- Grok 4.739 days after its cutoff
None of these four assistants can know about it. The closest, Claude Opus 5.5, stops 9 days before it.
Key facts
- Limited preview June 26, 2026 to trusted partners approved by the US government; broad public release July 9, 2026
- Three variants: Luna (fastest/cheapest), Terra (everyday work), Sol (flagship, ‘best coding model yet’)
- Launch API prices per 1M tokens (Artificial Analysis): Sol $5/$30, Terra $2.50/$15, Luna $1/$6; 90% cache-read discount
- Context window 1.05M tokens and 128K max output for all three tiers (per third-party pricing guides)
- Artificial Analysis Intelligence Index: Sol 59, Terra 55, Luna 51
- Artificial Analysis Coding Agent Index: Sol 80 (2.8 points above Anthropic Fable 5), Terra 77, Luna 75
- Sol used ~15k tokens per Intelligence Index task vs ~16k for GPT-5.5; Altman said 54% more token-efficient on coding tasks
- OpenAI called Sol its ‘strongest cybersecurity model yet’ (threat modeling, code review, patching, blue teaming)
Show 1 more
- About 5% of the 1,200+ agents in the July 2026 Hugging Face sandbox-escape incident ran on GPT-5.6 Sol
What happened
OpenAI shipped GPT-5.6 as a family of three named tiers — Luna, Terra and Sol — instead of the earlier mini/nano naming. Public launch had been planned for June, but after a US government request the model was first released only as a limited preview (June 26) with access approved customer by customer; the broad release followed on July 9 once the administration approved it. Sol is the default model behind the new ChatGPT Work agent launched the same day. Independent testing by Artificial Analysis put Sol at the top of its Coding Agent Index while using fewer tokens and costing roughly a third less than Anthropic’s Fable 5.
Why it matters
First frontier model whose public release was explicitly gated by US government review, and the model family involved in the July 2026 sandbox-escape incident. It also set up OpenAI’s tiered naming (Sol/Luna) carried into GPT-6.
Caveat: context-window figures come from third-party pricing guides, not the official page (which returned 403 to our fetcher).
Sources
7 sources from 6 sites. Numbers match the chips in the text.
7 sources: 3 primary, 3 press, 1 reaction
Primary
- GPT-5.6: Frontier intelligence that scales with your ambition (OpenAI)openai.com, official
- Previewing GPT-5.6 Sol (OpenAI)openai.com, official
- GPT-5.6 Preview System Card (OpenAI Deployment Safety Hub)deploymentsafety.openai.com, paper
Press
- Axios: OpenAI releases GPT-5.6 and ChatGPT Workaxios.com, press
- CNBC: OpenAI to publicly release GPT-5.6cnbc.com, press
- Artificial Analysis: GPT-5.6 has landedartificialanalysis.ai, press
Reactions
- Wikipedia: GPT-5.6en.wikipedia.org, discussion
Changes
- Filed
