ChatGPT

What is ChatGPT

ChatGPT, the full name of Chat Generative Pre-trained Transformer, is an AI chatbot launched by OpenAI. Based on the GPT series of large language models, through massive text pre-training and RLHF alignment optimization, it can conduct natural and smooth multiple rounds of conversations, answer questions, write articles, write code, and perform various language tasks. In May 2026, the default model has been upgraded to GPT-5.5 Instant, which is free and open to all users. It greatly reduces the hallucination rate while maintaining extremely fast response. It also adds a transparent management function of memory sources and is suitable for diverse scenarios such as intelligent customer service, content creation, educational assistance, and programming debugging.

OpenAI is a research and deployment company dedicated to ensuring that general artificial intelligence (AGI) can benefit all mankind. ChatGPT is an important achievement it has achieved in this field. It is also a direct application and important milestone of the GPT (Generative Pre-trained Transformer) series of models in the field of dialogue systems.

Name meaning analysis: Chat and GPT

"Chat", which means "chat" or "dialogue", directly points out the main interaction form and application scenarios of the product, as a chat robot that can have natural language conversations with users. Emphasize the model's ability to understand and generate conversations, providing a smooth, coherent and logical communication experience, making users feel like they are talking to an intelligent partner.

"GPT" is the abbreviation of "Generative Pre-trained Transformer", which summarizes the key technical characteristics of the model.

• Generative: Indicates that the model has the ability to generate text. It not only simply retrieves or matches existing information, but also creates new text content that is grammatical and logical based on the learned language rules and contextual information. ChatGPT can complete a variety of creative tasks such as writing articles, writing code, composing poetry, etc.
• Pre-trained: refers to the model being pre-trained on a large amount of unlabeled text data. Through this process, the model can automatically learn the structure, grammar, semantics and world knowledge of the language, and gain rich language understanding and generation capabilities. This enables the model to show better performance when facing specific downstream tasks with only a small amount of labeled data or even no labeled data.
• Transformer: It is the architecture of a deep learning model, proposed by Google in 2017, and has achieved great success in the field of natural language processing. The core of the Transformer architecture is the Self-Attention Mechanism, which can effectively capture long-distance dependencies in text sequences and process input data in parallel, greatly improving the efficiency and effectiveness of the model in processing long texts and complex language structures.

Main functions of ChatGPT

• Natural language dialogue: supports multiple rounds of continuous communication, understands contextual semantics, and provides a smooth and logical dialogue experience.
• Text generation and creation: Generate articles, stories, poems, and advertising copy based on prompts, and support imitation of specific writing styles.
• Translation and language learning: realize multi-language translation, provide grammar explanation and vocabulary assistance, and help users learn new languages.
• Knowledge Q&A: covering history, science, technology and other fields, answering various knowledge questions and summarizing complex information.
• Code programming and debugging: writing, interpreting and debugging multi-language code to assist developers in understanding complex code logic.
• Multi-modal content analysis: Supports uploading photos, charts, handwritten formulas and documents for visual-linguistic joint reasoning and information extraction.
• Memory and personalization: Automatically record user preferences and historical information, provide accurate recommendations based on past conversations, and support viewing and managing memory sources one by one.
• Real-time Internet search: Call the search tool to obtain the latest network information and break through the knowledge deadline limit.

Technical principles of ChatGPT

• Transformer self-attention architecture: Based on the GPT series generative pre-training Transformer architecture, it captures long-distance dependencies in text sequences through the self-attention mechanism, processes input data in parallel, and achieves efficient understanding and generation of complex semantics.
• Large-scale pre-training is aligned with RLHF: unsupervised pre-training is performed on massive unlabeled texts to learn language structure and world knowledge; output style and safety are optimized through human feedback reinforcement learning (RLHF) to make responses more in line with human preferences and values.
• Context learning and memory retrieval: jointly encode the current input and multiple rounds of conversation history, and use context learning to maintain conversation coherence; GPT-5.5 Instant introduces memory source technology, and the model retrieves relevant historical conversations, uploaded files and Gmail related content when it is generated, and explicitly attributes it on the interface.
• Autoregressive text generation: Use autoregressive decoding to predict output tags one by one, combine kernel sampling and temperature sampling to introduce reasonable randomness, and reduce false statements by 52.5% in high-risk areas through factual alignment and hallucination suppression technology.
• Multi-modal joint reasoning: Integrate visual-language understanding capabilities to jointly encode and reason images, scientific diagrams, handwritten formulas and complex documents, achieving significant improvements in accuracy on multi-modal benchmarks such as CharXiv and MMMU-Pro.

The core advantages of ChatGPT

• Significant reduction in hallucination rates: 52.5% reduction in false statements in high-risk fields such as medical, legal, and financial, making daily interactions more trustworthy and reliable.
• Reasoning and academic skills jumped: 81.2% on the AIME 2025 math test, 85.6% on the GPQA doctoral-level scientific reasoning, and greatly enhanced STEM problem solving.
• Natural and concise expression: Redundant formatting and meaningless emoticons are reduced through post-style training, reducing the word count by about 30% while retaining a warm tone.
• Memory is controllable and transparent: users can view, modify or delete personal memory entries that affect replies, avoiding interference from outdated information, and privacy is autonomously controllable.
• Multi-modality and tool enhancement: Supports photos, charts, document parsing and intelligent search calls, achieving a leap from plain text to visual-linguistic joint reasoning.
• Ecology and API improvement: The platform has a huge ecosystem of customized GPTs, the API supports chat-latest quick access, and is highly developer-friendly.

Comparison of similar competing products of ChatGPT

Product pricing for ChatGPT

• Free version (Free): $0/month, provides core model access, but there are strict quota limits for message sending, file upload, image generation and memory functions. It is suitable for basic users who are experiencing AI for the first time.
• Go: $8/month. Based on the free version, it increases the amount of messaging, uploading, image generation, memory and voice mode, but still uses the core model and does not include advanced features. It is suitable for light users with limited budget but who need to use it more frequently.
• Plus: $20/month (limited $0 discount for the first month, restored to original price from June 9, 2026), unlocks advanced models, expanded message and upload limits, Thinking advanced image creation, cross-chat memory, Codex encoding agents, in-depth research and customized GPT, which is the main choice for most professional users.
• Pro: $100/month, includes all Plus features and provides 5 times or 20 times the usage limit, Pro cutting-edge models, maximum access to Codex, the highest level of in-depth research, unlimited core chat and image generation, comprehensive memory and early access to experimental functions, suitable for high-frequency heavy users and professionals.

ChatGPT application scenarios

• Intelligent customer service and daily consultation: handle user problems 24/7, understand intentions and provide personalized answers, suitable for customer service scenarios such as e-commerce, finance, and government affairs.
• Marketing and content creation: Assist in writing advertising copy, social media posts, blog articles, and email marketing content to help brands reach target audiences efficiently.
• Education and scientific research assistance: Provide students with personalized tutoring, problem-solving ideas and knowledge explanations; summarize papers, analyze data charts, and assist researchers with academic writing.
• Programming development and debugging: generate code snippets, explain complex logic, troubleshoot bugs, support Python, JavaScript, C++ and other languages.
• High-risk professional consultation: In scenarios that require extremely high accuracy, such as interpretation of medical symptoms, analysis of legal clauses, and verification of financial data, it provides a credible reference with the advantage of reducing the hallucination rate by 52.5%.
• Personalized recommendations for life: Actively recommend restaurants, recipes, and travel plans based on historical memory, eliminating the need for users to repeatedly explain dietary taboos and preferences.

Advantages and limitations of ChatGPT

Advantage analysis

• Significant reduction in hallucination rates: 52.5% reduction in false statements in high-risk fields such as medical, legal, and financial, making daily interactions more trustworthy and reliable.
• Reasoning and academic skills jumped: 81.2% on the AIME 2025 math test, 85.6% on the GPQA doctoral-level scientific reasoning, and greatly enhanced STEM problem solving.
• Natural and concise expression: Redundant formatting and meaningless emoticons are reduced through post-style training, reducing the word count by about 30% while retaining a warm tone.
• Memory is controllable and transparent: users can view, modify or delete personal memory entries that affect replies, avoiding interference from outdated information, and privacy is autonomously controllable.
• Multi-modality and tool enhancement: Supports photos, charts, document parsing and intelligent search calls, achieving a leap from plain text to visual-linguistic joint reasoning.
• Ecology and API improvement: The platform has a huge ecosystem of customized GPTs, the API supports chat-latest quick access, and is highly developer-friendly.

Limitations and challenges

• Insufficient knowledge cutoff and real-time performance: ChatGPT is based on massive historical text pre-training, and the knowledge base reflects the state of the world during the cutoff period of the training data. For information about new events, new discoveries, new policies or dynamic changes that have occurred since then, it is impossible to provide accurate answers, or even give wrong answers based on outdated information.
• May generate misinformation and bias: Models generate text based on statistical patterns in training data, do not truly “understand” the true meaning of the content, and cannot fact-check like humans. As a result, content may be generated that sounds reasonable but is actually inaccurate, factual, or even completely fictitious (i.e., “hallucinations”), while biases present in the training data may be inherited and amplified by the model.
• Lack of true understanding and empathy of human emotions: ChatGPT is unable to truly experience joy, anger, sorrow, and joy, and cannot deeply understand the complexity and subtleties of human emotions. The "emotional" responses generated are more based on language patterns and common emotional expressions learned in the training data, rather than true feelings from the heart, and therefore cannot replace professional psychological counseling or emotional support.