The model reaches state-of-the-art status through many benchmarks, beats Fable and Mythos often, and scores a record on Arc-Agi-2 of 92.5% while being the first to actually solve a puzzle on Arc-Agi 3, measuring how it handles completely unknown situations.
GPT-5.6 comes in three versions; Sol as the flagship, top rated model, Terra as the mid-tier GPT-5.5-level model at half the price, and Luna as the dirt cheap model, likely comparable with GPT-5.4.
The pricing for Sol is at $5 input/$30 output, Terra is at $2.50 input/$25 output, and Luna ticks in at $1 input and $6 output, placing it in a good position to compete with the recently released Grok 4.5 and Muse Spark 1.1.
The Free and Go tiers on ChatGPT only get access to the Terra model, while Plus, Pro, Business and Enterprise can choose between all three, and set effort levels.
Pro and Enterprise users get Sol Pro in addition, which provides «the highest quality results on complex tasks.»
API users get access to the whole lot.
Read more: GPT-5.6 launch page.