OpenAI reportedly declared a “code red” on the 1st of December in response to increasingly credible competition from the likes of Google’s Gemini 3. It’s less than two weeks later and they just announced GPT-5.2, calling it “the most capable model series yet for professional knowledge work”. Key characteristics of GPT-5.2 – The new model comes in two variants: GPT-5.2 and GPT-5.2 Pro. There’s no Mini variant yet. GPT-5.2 is available via their UI in both “instant” and “thinking” modes, presumably still corresponding to the API concept of different reasoning effort levels. The knowledge cut-off date for both variants is now August 31st 2025. This is significant – GPT 5.1 and 5 were both Sep 30, 2024 and GPT-5 mini was May 31, 2024. Both of the 5.2 models have a 400,000 token context window and 128,000 max output tokens – no different from 5.1 or 5.

Full analysis : GPT-5.2 models have a 400K context window and 128K max output tokens, like GPT-5 and 5.1, but have an August 31, 2025, knowledge cutoff, vs. September 30, 2024.