Definition
Plain language
OpenAI's series of general-purpose AI models.
As stated in the literature
OpenAI's flagship LLM line and its successors, spanning multimodal chat models and later reasoning-tuned releases used widely as agent backbones.
Also called: GPT-4o, GPT-4 Turbo, GPT-4o-mini, GPT-4.1, GPT-5, GPT-5-mini, GPT-5-nano, GPT-5.1, GPT-5.2, GPT-5.2R, GPT-5.4, GPT-5.5, GPT-5.6
Why it matters: It set the expectations and pricing for the current generation of frontier chatbots, and successor models are still measured against it.
For example, GPT-4 was the model that popularized using ChatGPT for serious coding and writing tasks.
Heard on the show
“Frontier closed-source models — GPT-4, Claude, Gemini production — are off-limits to this style of analysis by construction.”Episode 004 — The Sycophancy Circuit That Survives Alignment Training