GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-5.4 unified OpenAIAn AI research company — created GPT, ChatGPT, DALL-E, and the o-series reasoning models.'s coding and reasoningStep-by-step logical thinking in AI models — chain-of-thought before answering hard problems. lines under one model name in ChatGPTOpenAI's conversational chat product — brought large language models to hundreds of millions of users. and Codex. It led benchmarks on OSWorld, BrowseComp, and GPQA Diamond while simplifying the model picker for developers who had juggled GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-5.x, o-series, and Codex variants.

GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-5.4 merged Codex-grade coding into OpenAIAn AI research company — created GPT, ChatGPT, DALL-E, and the o-series reasoning models.'s default reasoningStep-by-step logical thinking in AI models — chain-of-thought before answering hard problems. model.

One mainline model reduced fragmentation between chat, agents, and IDEIntegrated development environment — an editor with debugging, build tools, and project management built in. tooling.