A collection of 6 posts
There is no OpenAI model called GPT-5.6 Sol Ultra — the name is unverifiable and this page explains where it came from. What max reasoning effort actually costs on GPT-5.6 Sol and GPT-6 Astra, measured on Artificial Analysis's Intelligence Index v4.3.2, and how it compares with Claude Fable 5.
A neutral, source-led comparison of OpenAI GPT-5.6 (Sol, Terra, Luna) and Anthropic Claude Fable 5: pricing, intelligence and coding benchmarks, cost per task, and which to use.
OpenAI's GPT-5.6 Sol landed in limited preview while Claude Opus 4.8 is already GA. An honest look at pricing, context windows, benchmark claims, and how each behaves in Codex vs Claude Code — including why the public scores are suspect right now.
A practical GPT-5.6 vs GPT-5.5 comparison: what actually changed across the new Sol/Terra/Luna tiers, pricing, reasoning modes, benchmarks, and a clear decision guide on whether to upgrade or stay put.
OpenAI's GPT-5.6 family — Sol, Terra, Luna — tiers, current pricing after the July 30 cuts, Ultrafast and Cyber, benchmarks, and how to choose.
GPT-5.6 (Sol, Terra, Luna) hit general availability on July 9, 2026. Release timeline, the July 30 price cuts, Ultrafast, Cyber, and what to run now.