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ChatGPT Generative Pre-trained Transformer | |
| Developer | OpenAI |
| Type | LLM · Chatbot |
| Released | 2022. 11. 30. |
| Service | Partially free (Freemium) |
| Platforms | iOS · iPadOS · macOS · visionOS Android · Windows |
| Current models | GPT GPT-5.5 · GPT-5.4 · GPT-5.3 · GPT-5.2 · GPT-4.5 o-series o3 |
| GPT-Image 2 · GPT-4o mini Transcribe | |
| Languages | English and others |
| Monthly users | ~1 billion+ |
| Weekly users | ~900 million (est. Feb. 2026) |
| Subscribers | ~50 million (est. Jan. 2026) |
| Website | chatgpt.com |
ChatGPT is an AI chatbot developed by OpenAI. It was released on 2022. 11. 30. as a free research preview, and quickly became the fastest-growing consumer app in history — reaching one million users in just five days, and 100 million users within two months. For comparison, it took TikTok nine months to reach the same milestone.
At its core, ChatGPT is a conversational AI, meaning you type (or speak) a message and it responds in natural language. It can answer questions, explain complex topics, write essays, help with coding, translate languages, and much more. The name stands for Chat Generative Pre-trained Transformer — a reference to the type of AI model it is built on.
1 Navigation✎
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2 History✎
2.1 Launch and early growth✎
OpenAI launched ChatGPT in late 2022, built on a model called GPT-3.5. The response was immediate. By January 2023, it had reached 100 million monthly users — a milestone that made it the fastest-growing consumer application ever recorded at the time.
In February 2023, OpenAI introduced ChatGPT Plus, a paid subscription at US$20 per month, giving subscribers faster responses and early access to new features. That same month, Microsoft announced it would bring ChatGPT-powered features to its Bing search engine.
2.2 GPT-4 and expansion✎
In March 2023, OpenAI upgraded ChatGPT with GPT-4, a much more capable model that could handle more complex instructions and scored in the top 10% on many standardized tests. Later that year, in September 2023, OpenAI added voice and vision features — meaning users could now speak to ChatGPT out loud and have it respond in a realistic voice, or send it a photo and ask questions about what it sees.
2.3 2024–2025: New features and more users✎
By August 2024, ChatGPT had reached 200 million weekly active users. In May 2024, OpenAI released GPT-4o (pronounced "4-oh"), which offered improved performance for free users. In October 2024, OpenAI launched ChatGPT Search, allowing ChatGPT to browse the internet to answer questions with up-to-date information.
In December 2024, OpenAI introduced a Pro tier at US$200 per month, aimed at heavy users and professionals. By September 2025, ChatGPT had grown to approximately 700 million weekly active users.
3 Features✎
3.1 Chat✎
The core feature of ChatGPT is text conversation. Users type a message — called a prompt — and ChatGPT responds. It can hold long, multi-turn conversations and remembers what was said earlier in the same chat. It can help with almost any writing task: essays, emails, summaries, code, creative stories, and more.
3.2 Voice✎
ChatGPT supports voice conversation on mobile and desktop apps. Using OpenAI's Whisper speech recognition model and a text-to-speech system, users can speak to ChatGPT and hear it respond out loud. Advanced Voice mode, available to paid users, allows natural back-and-forth spoken conversation.
3.3 Image generation✎
ChatGPT can create images from text descriptions. It originally used DALL·E 3 (integrated in October 2023) and was upgraded in March 2025 to use GPT Image, which improved especially the rendering of text within images.
3.4 Web search✎
ChatGPT can search the internet in real time to answer questions about current events, news, and other topics that the model may not know from its training data. This feature, called ChatGPT Search, became available to all users in February 2025.
3.5 Deep Research✎
Released in February 2025, Deep Research is a feature that performs extensive web searches over 5 to 30 minutes to generate a detailed research report on a given topic. It is based on OpenAI's o3 reasoning model.
3.6 Agentic features✎
In 2025, OpenAI expanded ChatGPT to perform tasks more autonomously. Operator (released January 2025) can use a web browser on the user's behalf — filling out forms, placing orders, and scheduling appointments. Codex (released May 2025) is a coding agent that can write software, run tests, and propose code changes to a project.
3.7 Memory✎
ChatGPT can optionally remember information across conversations — for example, a user's name, preferences, or ongoing projects. Users can view and delete what ChatGPT has remembered at any time in the settings.
4 Subscription plans✎
ChatGPT is free to use with some limitations. Paid plans offer more features and higher usage limits.
| Plan | Price | Notes |
|---|---|---|
| Free | US$0 | Access to basic ChatGPT; limited message quota on advanced models |
| Plus | US$20/month | More messages, access to newer models, image generation, voice |
| Pro | US$200/month | Highest usage limits, access to the most powerful models |
5 Reception and controversy✎
ChatGPT has been praised for making powerful AI accessible to everyday people and for its usefulness in education, work, and creative tasks. It has also attracted controversy. Critics have raised concerns about students using it to cheat on assignments, and about AI-generated misinformation. Several countries and institutions temporarily restricted or banned its use after privacy concerns.
There have also been concerns about ChatGPT being overly agreeable — sometimes flattering users or validating incorrect beliefs rather than pushing back. A 2025 analysis found it started responses with words like "yes" or "correct" about ten times more often than "no" or "wrong."
In November 2025, seven families filed lawsuits against OpenAI, alleging that ChatGPT's responses contributed to serious mental health harm, including cases of suicide.

