GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-4.5 was OpenAIAn AI research company — created GPT, ChatGPT, DALL-E, and the o-series reasoning models.'s last major GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-4.x chat model: warmer tone, better factual recall, and strong creative writing. It bridged GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-4o and the unified GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-5 system — and briefly served as the top ChatGPTOpenAI's conversational chat product — brought large language models to hundreds of millions of users. tier for users who wanted scale without o-series reasoningStep-by-step logical thinking in AI models — chain-of-thought before answering hard problems. latency.

GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-4.5 was OpenAIAn AI research company — created GPT, ChatGPT, DALL-E, and the o-series reasoning models.'s final large chat-model release before the GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-5 generation.

It showed incremental scaling still mattered for conversational quality and knowledge work.