ChatGPT

What is ChatGPT?

ChatGPT, short for Chat Generative Pre-trained Transformer, is an AI chatbot launched by OpenAI. Based on the GPT series of large language models, it is optimized through massive text pre-training and RLHF alignment, enabling natural and fluent multi-turn conversations, answering questions, writing articles, writing code, and performing various language tasks. In May 2026, the default model was upgraded to GPT-5.5 Instant , which is freely available to all users. While maintaining extremely fast response, it significantly reduces the hallucination rate and adds a transparent memory source management function, making it 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 artificial general intelligence (AGI) benefits all mankind. ChatGPT is an important achievement in this field and a direct application and significant milestone of the GPT (Generative Pre-trained Transformer) series of models in the field of dialogue systems.

Name Meaning Explanation: Chat and GPT

” Chat ,” meaning “conversation” or “talking,” directly indicates the product’s main interaction method and application scenario: a chatbot capable of engaging in natural language dialogue with users. It emphasizes the model’s ability to understand and generate dialogue, providing a smooth, coherent, and logical communication experience, making users feel as if they are conversing with an intelligent companion.

“ GPT ” is an abbreviation for “ Generative Pre-trained Transformer ”, which summarizes the key technical characteristics of the model.

Generative : This indicates that the model has the ability to generate text. It goes beyond simply retrieving or matching existing information; it creates entirely new, grammatically and logically correct text content based on learned language rules and contextual information. This enables ChatGPT to perform various creative tasks such as writing articles, coding, and composing poetry.
Pre-trained refers to models that have been pre-trained on a large amount of unlabeled text data. Through this process, the model can automatically learn the structure, syntax, semantics, and world knowledge of the language, gaining rich language understanding and generation capabilities. This allows the model to perform well even with only a small amount of labeled data or no labeled data when facing specific downstream tasks.
Transformer : A deep learning model architecture proposed by Google in 2017, it 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, process input data in parallel, and greatly improve the efficiency and effectiveness of the model in processing long texts and complex language structures.

ChatGPT’s main functions

Natural Language Dialogue : Supports multi-turn continuous communication, understands contextual semantics, and provides a smooth and logically clear 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 : Enables multilingual translation, provides grammar explanations and vocabulary assistance, and helps users learn new languages.
Knowledge Q&A : Covering fields such as history, science, and technology, answering various knowledge-based questions and summarizing complex information.
Code Programming and Debugging : Write, interpret, and debug multi-language code to help developers understand complex code logic.
Multimodal content analysis : Supports uploading photos, charts, handwritten formulas, and documents for visual-language joint reasoning and information extraction.
Memory and Personalization : Automatically records user preferences and historical information, provides accurate recommendations based on past conversations, and supports viewing and managing memory sources one by one.
Real-time online search : Utilize search tools to obtain the latest online information, overcoming the limitations of knowledge deadlines.

ChatGPT’s technical principles

Transformer Self-Attention Architecture : Based on the GPT series of generative pre-trained Transformer architectures, it captures long-distance dependencies in text sequences through a self-attention mechanism, processes input data in parallel, and achieves efficient understanding and generation of complex semantics.
Large-scale pre-training aligned with RLHF : Unsupervised pre-training on massive amounts of unlabeled text to learn language structure and world knowledge; optimization of output style and security through human feedback reinforcement learning (RLHF) to make responses more in line with human preferences and values.
Contextual learning and memory retrieval : The current input is jointly encoded with the history of multiple rounds of dialogue, and contextual learning is used to maintain the coherence of the dialogue; GPT-5.5 Instant introduces memory source technology, and the model retrieves relevant historical dialogues, uploaded files and Gmail related content when generating, and explicitly attributes them in the interface.
Autoregressive text generation : It uses an autoregressive decoding method to predict output tags one by one, and introduces reasonable randomness by combining kernel sampling and temperature sampling. At the same time, through factual alignment and illusion suppression technology, it reduces false statements by 52.5% in high-risk areas.
Multimodal Joint Reasoning : Integrating visual-language understanding capabilities, it performs joint encoding and reasoning on images, scientific charts, handwritten formulas, and complex documents, achieving significant accuracy improvements on multimodal benchmarks such as CharXiv and MMMU-Pro.

ChatGPT’s core advantages

The rate of hallucinations has decreased significantly : In high-risk fields such as medicine, law, and finance, false statements have decreased by 52.5%, and daily interactions are more credible and reliable.
Reasoning and academic abilities have improved dramatically : 81.2% of AIME 2025 math tests were completed, 85.6% of GPQA doctoral-level scientific reasoning tests were completed, and STEM problem-solving skills were significantly enhanced.
Natural and concise expression : Post-style training reduces redundant formatting and meaningless emojis, reducing word count by about 30% while retaining a warm tone.
Controllable and transparent memory : Users can view, correct, or delete personal memory entries that affect responses, avoiding interference from outdated information and ensuring their privacy is under their control.
Multimodal and tool enhancements : Supports photo, chart, and document parsing and intelligent search, enabling a leap from plain text to visual-language joint reasoning.
Comprehensive Ecosystem and API : The platform boasts a vast custom GPTs ecosystem, and its API supports rapid integration via chat-latest, making it highly developer-friendly.

ChatGPT’s Competitive Product Comparison

Comparison Dimensions	ChatGPT	Kimi Smart Assistant	Claude
Core positioning	AI dialogue and content generation, with an emphasis on deep reasoning and programming.	Long text processing and intelligent search focus on information integration	A safe and controllable AI assistant, focusing on deep analysis and long text understanding.
Conversational skills	Multi-turn contextual coherence supports complex reasoning and code debugging.	Supports extremely long contexts of up to 2 million words, suitable for literature and report analysis.	Proficient in deep reasoning and nuanced dialogues, with accurate understanding of long texts, suitable for academic and professional analysis.
Real-time knowledge	Built-in search tool that can proactively obtain real-time network information	Strong network search capabilities, real-time information integration and tracing	The knowledge is current as of the training date; real-time information needs to be supplemented through the search plugin.
Multimodal capabilities	Supports image, chart, handwritten formula, and PDF parsing and inference.	Supports parsing multiple formats including images, PDFs, web pages, and PPTs.	Supports image, PDF, and document parsing and visual analysis; robust multimodal inference.
Memory and Personalization	A new “Memory Source” panel has been added, allowing users to view, correct, or delete individual memories.	Supports long-term memory and maintains user preferences across sessions.	Supports cross-session projects and long-term memory; allows users to upload documents to build their own knowledge base.
Ecological integration	The custom GPTs ecosystem is vast, with abundant APIs and third-party tools.	Supports WeChat Mini Programs, browser plugins, and web platforms.	The API ecosystem is well-developed and highly integrated with office tools such as Slack and Notion.
Usage threshold	Access from within China requires a stable internet connection. You will also need to register an OpenAI account.	Direct access within China, supports registration-free trial, one-click login with mobile number.	Access within China requires a stable internet connection and registration of an Anthropic account; access may be restricted in some regions.
Special features	Code generation, in-depth research, custom GPT, multilingual translation	Generate PPTs, mind maps, meeting minutes, and web page summaries with one click.	Artifacts offers real-time preview, in-depth document analysis, and outstanding security and controllability.

ChatGPT’s product pricing

Free version : $0/month, provides access to the core model, but message sending, file upload, image generation and memory functions are subject to strict limits, suitable for basic users who are new to AI.
Go : $8/month. It offers increased spending on messaging, uploading, image generation, memory, and voice modes compared to the free version, but still uses the core model and does not include advanced features. It is suitable for light users with limited budgets who need to use the app more frequently.
Plus : $20/month (first month $0 for a limited time, price will return to normal on June 9, 2026), unlocks advanced models, extended messaging and upload limits, Thinking advanced image creation, cross-chat memory, Codex coding agents, deep research and custom GPT, making it the primary choice for most professional users.
Pro : $100/month, includes all Plus features and provides 5x or 20x usage credit, Pro cutting-edge models, maximum access to Codex, the highest level of in-depth research, unlimited core chat and image generation, full memory, and early access to experimental features. Suitable for high-frequency heavy users and professionals.

Application scenarios of ChatGPT

Intelligent customer service and daily consultation : Handles user issues 24/7, understands intent and provides personalized answers, suitable for customer service scenarios such as e-commerce, finance, and government.
Marketing and Content Creation : Assist in writing advertising copy, social media posts, blog articles, and email marketing content to help brands reach their target audience efficiently.
Educational and research support : Providing students with personalized tutoring, problem-solving strategies, and knowledge explanations; and assisting researchers in summarizing papers, analyzing data charts, and writing academic papers.
Programming development and debugging : Generate code snippets, explain complex logic, and troubleshoot bugs. Supports multiple languages such as Python, JavaScript, and C++.
High-risk professional consultation : In scenarios where accuracy is extremely important, such as medical symptom interpretation, legal clause analysis, and financial data verification, reliable references are provided by leveraging the advantage of a 52.5% reduction in hallucination rate.
Personalized lifestyle recommendations : Based on historical memories, the system proactively recommends restaurants, recipes, and travel plans, eliminating the need for users to repeatedly explain their dietary restrictions and preferences.

Advantages and limitations of ChatGPT

Advantages Analysis

The rate of hallucinations has decreased significantly : In high-risk fields such as medicine, law, and finance, false statements have decreased by 52.5%, and daily interactions are more credible and reliable.
Reasoning and academic abilities have improved dramatically : 81.2% of AIME 2025 math tests were completed, 85.6% of GPQA doctoral-level scientific reasoning tests were completed, and STEM problem-solving skills were significantly enhanced.
Natural and concise expression : Post-style training reduces redundant formatting and meaningless emojis, reducing word count by about 30% while retaining a warm tone.
Controllable and transparent memory : Users can view, correct, or delete personal memory entries that affect responses, avoiding interference from outdated information and ensuring their privacy is under their control.
Multimodal and tool enhancements : Supports photo, chart, and document parsing and intelligent search, enabling a leap from plain text to visual-language joint reasoning.
Comprehensive Ecosystem and API : The platform boasts a vast custom GPTs ecosystem, and its API supports rapid integration via chat-latest, making it highly developer-friendly.

Limitations and challenges

Insufficient knowledge cutoff and real-time performance : ChatGPT is pre-trained on massive amounts of historical text, and its knowledge base reflects the state of the world at the time the training data was last updated. It cannot provide accurate answers to new events, discoveries, policies, or dynamic changes that have occurred since then, and may even provide incorrect answers based on outdated information.
It may generate misinformation and bias : The model generates text based on statistical patterns in the training data, but does not truly “understand” the real meaning of the content and cannot perform fact-checking like a human. Therefore, it may generate content that sounds reasonable but is actually inaccurate, inconsistent with the facts, or even completely fictitious (i.e., “illusion”). At the same time, biases present in the training data may be inherited and amplified by the model.
Lacking genuine human emotional understanding and empathy : ChatGPT cannot truly experience joy, anger, sorrow, or happiness, nor can it deeply understand the complexity and subtlety of human emotions. The generated “emotional” responses are more based on language patterns and common emotional expressions learned from training data, rather than genuine feelings from the heart, and therefore cannot replace professional psychological counseling or emotional support.