GPT-5.6 (and the 2026 GPT-5.x line)
OpenAI's mid-2026 flagship family: Luna, Terra and Sol tiers.
You're looking at an AI model record: who built it, what it can do, and the hardware and data behind it.
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.
Specifications & key facts
Each figure is labeled by basis: vendor spec, vendor claim, reported, estimate, or official. "Not publicly disclosed" means exactly that — we never invent values.
Overview
How this connects to the rest of the stack
This record's links at a glance — click a group to jump to it.
Developed by
Benchmarked on
Successor to
Competes with
Sources
OpenAI — Introducing GPT-5.5 ↗ · CNBC on GPT-5.6 (Jul 2026) ↗ · TechCrunch on GPT-Live voice models ↗
Record reviewed as of 2026-08-31 — see Methodology.