GPT-5.6 SOL
GA July 9, 2026. 1M-token context, top-tier reasoning and coding, vision, native web search. $5/$30 per million tokens — with Terra ($2.50/$15) and Luna ($1/$6) siblings sharing the same 1M window.
GPT-5.6 Sol is OpenAI's flagship model, generally available since July 9, 2026, and the top of the three-variant GPT-5.6 family: Sol (flagship, $5/$30 per million tokens), Terra (production workhorse, $2.50/$15), and Luna (high-volume tier, $1/$6). The family's defining move is that all three variants ship the same 1M-token context window — for the first time, OpenAI's cheap tier reads as much as its flagship. Sol itself delivers top-tier reasoning and coding with vision input and native web search. Versus its predecessor GPT-5.5, Sol holds the same $5/$30 price while expanding context from 400K to 1M and raising the reasoning and coding ceiling. The case for Sol: the hardest reasoning and agentic coding tasks in the OpenAI ecosystem, and any workload that needs flagship quality across a whole repository in one call. The case against: most production traffic — Terra covers the standard workload at half the price, and Luna makes 1M-context fan-outs nearly free. Pick the variant by workload, not by brand.
All three variants went GA on July 9, 2026 and share the 1M context window, vision input, and native web search. They differ in capability ceiling and price:
Terra and Luna are covered here rather than on separate pages because the spec deltas are price and ceiling, not features. All three are live in Council AI's lineup.
All three GPT-5.6 variants — Sol, Terra, and Luna — are available on every paid Council AI plan (Plus, Pro, Ultra). In practice Sol takes the flagship seat in high-stakes councils while Terra and Luna serve as the OpenAI voice in cost-balanced ones. Each council fans your prompt out in parallel to models from up to 8 other labs, and the moderator synthesizes a consensus answer with an agreement score — so a Sol + Fable 5 + Gemini 3.5 Flash council gives you three independent frontier opinions for less than many single-vendor workflows.
Capability ceiling and price. Sol is the flagship ($5/$30 per 1M) for top-tier reasoning and coding; Terra is the production workhorse ($2.50/$15); Luna is the high-volume tier ($1/$6). All three share a 1M-token context window, vision, and native web search, and all went GA on July 9, 2026.
$5.00 per million input tokens and $30.00 per million output tokens — the same sticker as GPT-5.5 before it. Terra costs $2.50/$15 and Luna $1/$6.
1,000,000 tokens on every variant — Sol, Terra, and Luna alike. That's the family's defining upgrade over GPT-5.5.
Same $5/$30 price, larger 1M context (up from GPT-5.5's 400K), and a higher reasoning and coding ceiling. GPT-5.5 remains available, but Sol is the better model at the same cost.
Effectively yes — OpenAI deprecated o3 in July 2026, and the GPT-5.6 family's built-in reasoning covers the workloads o3 specialized in.
Yes — Sol, Terra, and Luna are all live on every paid plan (Plus, Pro, Ultra), running in parallel councils with models from 8 other labs and consensus scoring.