ChatGPT is a generative artificial intelligence chatbot developed by OpenAI, first released to the public on November 30, 2022. Built on large language models, specifically generative pre-trained transformers (GPTs), it generates text, speech, and images in response to user prompts. The launch marked a pivotal moment in the history of artificial intelligence, triggering an accelerated period of investment, research, and public debate known as the AI boom. Within two months, ChatGPT reached 100 million monthly active users, making it one of the fastest-growing consumer applications in history. By February 2026, it reported 900 million weekly active users. OpenAI operates the service on a freemium model, offering both free and paid tiers. The product's rapid adoption and capabilities have sparked discussions about creativity, knowledge work, and the ethical implications of AI-generated content, including concerns about misinformation, bias, and academic dishonesty.
Background and Development
OpenAI, founded in 2015 as a nonprofit AI research organization, had already developed several influential models before ChatGPT. The company's GPT series, introduced with the Transformer architecture in 2018, demonstrated the potential of scaling up language models. The release of GPT-3 in 2020, with 175 billion parameters, showed that large models could perform a wide range of tasks with minimal fine-tuning. However, these models were not directly accessible to the general public. ChatGPT was built on a variant of GPT-3.5, fine-tuned using reinforcement learning from human feedback (RLHF), a technique that aligns model outputs with human preferences. This approach allowed ChatGPT to follow instructions, maintain conversational context, and refuse harmful requests, making it more usable and engaging than previous models. The development team, led by figures such as Brad Lightcap and Jakob Uszkoreit, drew on advances in neural networks, deep learning, and multi-head attention mechanisms.
Public Release and Immediate Impact
The public launch on November 30, 2022, was met with unprecedented enthusiasm. Within five days, over one million users had signed up, and the service frequently hit capacity limits due to overwhelming demand. The chatbot's ability to produce coherent essays, code, and creative content on demand captured the imagination of both technologists and the general public. News outlets, social media platforms, and academic institutions quickly began discussing its implications. The launch also intensified competition among AI companies. Anthropic, founded by former OpenAI researchers, released its own chatbot Claude in 2023. Google DeepMind and other major tech firms accelerated their AI research and product development. The AI boom led to significant investments in generative AI startups and infrastructure, including specialized chips from companies like Nvidia (though not in the provided list, the context is implied) and cloud services from Amazon Web Services, Microsoft Azure, and Google Cloud.
Features and Capabilities
ChatGPT is designed to handle a wide variety of tasks. It can write and debug computer programs, compose music, scripts, stories, and essays, answer questions (sometimes at a level exceeding that of an average human test-taker), and generate business concepts. It is frequently used for translation and summarization, and can simulate interactive environments such as a Linux terminal, a multi-user chat room, or simple text-based games like tic-tac-toe. Users interact through conversations consisting of text, audio, and image inputs and outputs, referred to as prompts. An optional 'Memory' feature allows users to instruct ChatGPT to remember specific information, and another option lets it recall old conversations. GPT-based moderation classifiers are used to reduce the risk of harmful outputs. In March 2023, OpenAI added support for plugins, including web browsing and code interpretation, as well as external plugins from developers such as Expedia, OpenTable, and Zapier. From October to December 2024, ChatGPT Search was deployed, allowing the chatbot to search the web for more accurate and up-to-date responses, increasing competition with major search engines. In December 2024, OpenAI launched a feature allowing users to call ChatGPT with a telephone for up to 15 minutes per month for free. In October 2025, OpenAI launched ChatGPT Atlas, a browser integrating the assistant directly into web navigation, with an 'agentic mode' that can take online actions for the user.
Paid Tiers and Mobile Apps
ChatGPT was initially free to the public and remains free in a limited capacity. In February 2023, OpenAI launched ChatGPT Plus, a premium service costing US$20 per month. The paid plan offered priority access, faster response times, and access to newer models. In December 2024, a Pro tier at $200 per month was introduced, coinciding with the release of the o1 reasoning model. In August 2025, ChatGPT Go was offered in India for ₹399 per month, with higher limits than the free version. Mobile apps for iOS and Android were released between May and July 2023, and a Windows app launched on the Microsoft Store on October 15, 2024. These apps expanded accessibility, allowing users to interact with ChatGPT on the go.
Language Support and Localization
OpenAI has made efforts to improve ChatGPT's performance in non-English languages. In 2022, the company met with Icelandic President Guðni Th. Jóhannesson, and in 2023, worked with a team of 40 Icelandic volunteers to fine-tune ChatGPT's Icelandic conversation skills as part of Iceland's attempts to preserve the language. In 2023, ChatGPT (based on GPT-4) was better able to translate Japanese to English when compared to Bing, Bard, and DeepL Translator. In December 2023, the Albanian government decided to use ChatGPT for rapid translation of European Union documents and analysis of required changes for Albania's EU accession. Several studies have shown that ChatGPT can outperform Google Translate in some mainstream translation tasks, though as of 2024, no machine translation services match human expert performance.
GPTs, Plugins, and Deep Research
In November 2023, OpenAI released GPT Builder, a tool allowing users to customize ChatGPT's behavior for specific use cases. These customized systems are referred to as GPTs. In January 2024, OpenAI launched the GPT Store, a marketplace for GPTs, which at launch included more than 3 million GPTs created by users. In September 2025, OpenAI added support for the Model Context Protocol (MCP) to ChatGPT apps, enabling improved third-party access to ChatGPT tools and servers. In July 2026, ChatGPT apps were renamed to plugins. In February 2025, OpenAI released Deep Research, a feature that generates reports based on extensive web searches, initially based on the reasoning model o3, taking from 3 to 30 minutes per report.
Image Generation and Agents
In October 2023, OpenAI integrated its image generation model DALL-E 3 into ChatGPT, using the chatbot to write prompts for DALL-E guided by conversations. In March 2025, OpenAI updated ChatGPT to generate images using GPT Image instead of DALL-E, significantly improving text generation within images, though this ability is noticeably worse in non-Latin alphabets. The model can also generate new images based on existing ones, and images are generated with C2PA metadata to verify they are AI-generated. In 2025, OpenAI added several agentic features. In January, Operator was released, capable of autonomously performing tasks through web browser interactions, including filling forms, placing online orders, scheduling appointments, and other browser-based tasks.
Reception and Controversies
ChatGPT's launch generated both enthusiasm and criticism. Proponents highlighted its potential to transform professional fields, while critics pointed out limitations and risks. The chatbot can generate incorrect or nonsensical answers that sound plausible, known as hallucinations. Biases in its training data have been reflected in its responses. It can facilitate academic dishonesty, generate misinformation, and create malicious code. The ethics of its development, particularly the use of copyrighted content as training data, have drawn controversy. These issues have sparked public debate about the nature of creativity and the future of knowledge work, and have led to calls for regulation and responsible AI development.