GPT-5.6 (and the 2026 GPT-5.x line) ☆

OpenAI moved to a fast cadence through 2026: GPT-5.4 (March 5, in Thinking and Pro variants, with mini and nano following) and GPT-5.5 (April, pitched at complex coding, research and data analysis) led to GPT-5.6 on July 9, 2026 — a family in three tiers, Luna, Terra and Sol, with Sol the frontier variant carrying OpenAI's strongest coding, science and cybersecurity capabilities and its most advanced safety stack. Alongside them, the GPT-Live-1 full-duplex voice models (July 2026) speak and listen simultaneously for natural conversation and live translation. Parameters remain undisclosed.