ChatGPT is a chatbot and virtual assistant developed by OpenAI and launched on November 30, 2022. Based on large language models (LLMs), it enables users to refine and steer a conversation towards a desired length, format, style, level of detail, and language.

Successive user prompts and replies are considered at each conversation stage as context.ChatGPT is credited with starting the AI boom, which has led to ongoing rapid investment in and public attention to the field of artificial intelligence.

By January 2023, it had become what was then the fastest-growing consumer software application in history, gaining over 100 million users and contributing to the growth of OpenAI's current valuation of $86 billion. ChatGPT's release spurred the release of competing products, including Gemini, Claude, Llama, Ernie and Grok.

Microsoft launched Copilot, now based on OpenAI's GPT-4o. Some observers raised concern about the potential of ChatGPT and similar programs to displace or atrophy human intelligence, enable plagiarism, or fuel misinformation.

ChatGPT is built on OpenAI's proprietary series of generative pre-trained transformer (GPT) models and is fine-tuned for conversational applications using a combination of supervised learning and reinforcement learning from human feedback. ChatGPT was released as a freely available research preview, but due to its popularity,

OpenAI now operates the service on a freemium model. Users on its free tier can access GPT-4o and GPT-3.5. The ChatGPT subscriptions "Plus", "Team" and "Enterprise" provide additional features such as DALL-E 3 image generation and increased GPT-4o usage limit.