Simon Willison / Simon Willison's Newsletter : GPT-5.2 models match GPT-5 and 5.1 with a 400K context window and 128K max output tokens, but have a newer knowledge cutoff of Aug. 31, 2025 vs. Sept. 30, 2024 —  Plus a YouTube video, a podcast appearance and more  —  In this newsletter:  — GPT-5.2  — Useful patterns for building HTML tools