ChatGPT, developed by OpenAI and launched in November 2022, has revolutionized the AI landscape by providing a versatile conversational interface powered by generative pre-trained transformer models, currently utilizing GPT-5 for enhanced reasoning, multimodal processing, and real-time interactions. It excels in understanding and generating human-like text, speech, and images based on user prompts, making it suitable for tasks ranging from answering queries and debugging code to composing essays, simulating scenarios, and even performing autonomous actions via integrated agents. The tool operates on a freemium model, with free access offering basic functionalities using models like GPT-4o mini, while paid tiers such as Plus ($20/month), Pro ($200/month), Team, and Enterprise unlock advanced features including higher usage limits, priority access to new models like OpenAI o3 for complex reasoning in coding, math, and science, and unlimited access to tools like Advanced Voice Mode for natural spoken conversations.

Key evolutions include the introduction of ChatGPT Search in October 2024 for real-time web information with citations, Deep Research in February 2025 for synthesizing multi-source reports in minutes, and agentic capabilities like Operator (January 2025) for browser-based tasks such as form filling and scheduling, Codex for software development including writing code and proposing pull requests, and the full ChatGPT Agent (July 2025) that combines these for multistep workflows on a virtual machine. Users can customize experiences through GPT Builder for creating specialized GPTs, accessible via the GPT Store with over 3 million user-created variants. Additional features encompass file uploads for analysis (e.g., PDFs, spreadsheets), image generation and editing with GPT-4o, Canvas for collaborative editing, and Scheduled Tasks for proactive reminders. Safety measures include the Moderation API to filter offensive content, memory controls for conversation retention, and opt-out options for data usage in training. Despite its strengths, ChatGPT faces challenges like occasional hallucinations, biases from training data, and dependency on user prompt quality, but ongoing updates via reinforcement learning from human feedback (RLHF) continue to refine accuracy and ethical alignment. As of May 2025, it ranks among the top five most-visited websites globally, underscoring its massive adoption and impact on productivity, education, and creativity across industries.