GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-5 merged OpenAIAn AI research company — created GPT, ChatGPT, DALL-E, and the o-series reasoning models.'s chat and reasoningStep-by-step logical thinking in AI models — chain-of-thought before answering hard problems. lines into one default model: stronger coding, math, health, and vision with automatic thinking when needed. GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-5 Pro added scaled test-time compute for the hardest tasks — resetting the consumer AI baseline the way GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-4 did in 2023.

GPTGenerative Pre-trained Transformer — OpenAI's family of large language models from GPT-1 through GPT-5.-5 unified OpenAIAn AI research company — created GPT, ChatGPT, DALL-E, and the o-series reasoning models.'s fragmented model picker into one flagship system.

Automatic reasoningStep-by-step logical thinking in AI models — chain-of-thought before answering hard problems. routing made frontier intelligence the default, not a power-user toggle.