GPT-5.6

Overview

OpenAI's current model family, released July 9, 2026. GPT-5.6 ships in three variants — Sol (workhorse), Terra (intermediate), and Luna (budget) — spanning enterprise work, coding, and scientific research across ChatGPT, Codex, and the API.

Why it matters

GPT-5.6 is OpenAI's answer to a market that now expects a full model ladder, not a single flagship: the Sol/Terra/Luna split mirrors the tiered strategy Anthropic and Google run, letting buyers match spend to task difficulty inside one vendor relationship. Coming roughly seven months after GPT-5.2, it also illustrates how short the flagship cycle has become — teams that pin a model version should plan for at least two migrations a year. For CTOs, the practical question is less 'which vendor leads the benchmark' and more which ladder integrates best with existing tooling, since all three major vendors now refresh their top tier in months, not years.