GPT-5.6 Preview: 1.5M Context, Agentic-First Design & Codex UltraFast

GPT-5.6 Rumors Heat Up as Users Swear ChatGPT Suddenly Got Smarter - Decrypt

OpenAI A/B tests GPT-5.6 in ChatGPT, showing stronger 3D design and reasoning vs 5.5 Pro despite longer response times (60 min). Stealth testing reveals competitive pressure from Anthropic's Fable 5 and China's GLM-5.2, forcing OpenAI to accelerate model release.