What Is ChatGPT? (The Complete 2026 Guide)
ChatGPT is an AI chatbot developed by OpenAI that understands plain English and generates human-like responses. It can answer questions, write content, summarise documents, generate images, help with code, and assist with a wide range of everyday tasks. Free to use with an OpenAI account, it has been the world's most-used AI tool since its launch in November 2022.
Chances are ChatGPT has already appeared in your life somehow. A colleague uses it to draft emails, a friend asks it for recipes, or your children use it for homework, and you are still not quite sure what it is or whether it is worth your time. That is exactly who this guide is for.
By the end of this page you will know what ChatGPT is, who makes it, how it works, what it costs, whether it is safe, and how to start using it today. Everything is explained in plain English, with no assumed knowledge and no jargon left unexplained.
Whatischatgpt.co.uk is an independent guide to ChatGPT, written and updated by our editorial team as the product changes. You can read more about who we are before you trust a word we say.
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What Does ChatGPT Stand For?
ChatGPT stands for Chat Generative Pre-trained Transformer. The GPT part describes the technology inside it, and each word means something specific:
**Generative** means the AI creates new content, rather than just retrieving or copying something that already exists.
**Pre-trained** means it was trained on enormous datasets before it was released, so it arrives already knowing a great deal about how language works.
**Transformer** refers to the neural network architecture the model is built on, which is particularly good at understanding the relationships between words in a sentence.
Put the three together and the name does exactly what it says: an AI that generates text, having been trained in advance, using an architecture called a transformer. The word Chat on the front simply tells you what you do with it. You chat with it.
You will also see GPT used on its own, for example in GPT-6, the current family of models. Each numbered release is a new and generally more capable generation of the same underlying technology. When someone says ChatGPT runs on GPT-6, they mean the chatbot is the interface and GPT-6 is the engine inside it.
Who Made ChatGPT?
ChatGPT was made by OpenAI, an AI research company founded in 2015 and based in San Francisco. The company's current CEO is Sam Altman. Microsoft has invested at least $13 billion in OpenAI and provides much of the computing power behind its products through its Azure cloud platform.
OpenAI is structured as a nonprofit that controls a for-profit subsidiary. Its stated mission is to ensure that artificial general intelligence benefits all of humanity, and ChatGPT is its best-known product.
ChatGPT launched on 30 November 2022 and reached one million users in five days, which made it the fastest-growing consumer application in history at the time. As of October 2026 it runs on OpenAI's GPT-6 family of models, with GPT-6 Astra as the flagship engine released in September 2026, and hundreds of millions of people now use it every week.
How Does ChatGPT Work?
ChatGPT is a large language model, which means it is a program trained to predict what text should come next in a conversation. Here is the process in plain English:
You type a question or request. This is called a prompt.
ChatGPT converts your words into a numerical representation it can process.
It compares your input against the patterns it learned from its training data, which covered enormous amounts of text.
It generates a response one word at a time, each time predicting the most likely continuation.
Human trainers gave feedback during its development to make the answers helpful, honest and safe. This process is called reinforcement learning from human feedback.
The important thing to understand is that ChatGPT does not look up answers in a database. It generates them from patterns, which is why it can be brilliantly creative and occasionally confidently wrong. We cover that in more detail in the limitations section below.
A useful mental model: think of ChatGPT as an extremely well-read colleague who has read a large share of the public internet and is very good at putting sentences together, but who never tells you which book an idea came from unless you ask.
What Can ChatGPT Do?
The short answer is: a lot. The longer answer is that ChatGPT handles anything that involves words, and on paid plans it works with images, files and voice too. Here are the most common things people use it for:
Answering questions on almost any topic
Writing emails, articles, essays and social media posts
Summarising long documents, PDFs and reports
Generating and editing images
Writing, explaining and debugging computer code
Translating text between languages
Brainstorming ideas and working through problems
Creating spreadsheets, presentations and outlines
Holding spoken conversations using voice mode
Searching the web for up-to-date information
Helping with job applications, including CVs and cover letters
Analysing uploaded files such as PDFs, spreadsheets, images and audio
Exactly which of these are available depends on your plan. Free accounts can handle most everyday tasks, while paid plans unlock more powerful models, higher limits and features such as expanded image generation and Deep Research. If you want to see one capability in depth, our guide to what ChatGPT can do with images is a good place to start.
Is ChatGPT Free?
Yes. ChatGPT has a free version, and for many people it is all they ever need. Paid plans exist for heavier users who need more power, higher limits and advanced features. Here is how the plans compare:
**Free:** $0 per month. Access to the GPT-6 Luna model, unlimited text chats, limited use of the smarter tools, image creation and voice.
**ChatGPT Go:** $8 per month. More messages, uploads, image creation and voice, plus longer memory. May include ads.
**ChatGPT Plus:** $20 per month. Access to the GPT-6 Sol and GPT-6 Astra models, expanded image creation, Deep Research, projects and tasks.
**ChatGPT Pro:** from $100 per month. Your choice of usage tiers, Pro reasoning with GPT-6 Astra, an agent called Dots, and maximum deep research.
Pricing is listed in US dollars on OpenAI's own pricing page, and Business and Enterprise plans are available separately for teams and organisations. For a fuller breakdown of what each plan includes and who each one suits, read our updated guide to ChatGPT plans.
How to Use ChatGPT for Beginners (Step by Step)
Getting started takes about two minutes. Here is the whole process:
Go to chatgpt.com and create a free account. You can sign up with an email address, or follow our guide to signing in with Google if that is easier.
Type your question or request into the message box.
Press Enter, or tap the send button.
Read the response. If it is not quite what you wanted, follow up with a clarifying message. ChatGPT remembers the conversation, so you do not need to repeat yourself.
Start a new conversation by clicking New chat whenever you change topic.
Good prompts get better answers. Be specific about what you want, give the context that matters, and say what format you would like the answer in. Compare tell me about marketing with write a 100-word Instagram caption for my bakery's new cinnamon rolls, using a friendly tone. The second one works because ChatGPT knows exactly what to aim at.
One more habit worth building early: ask for options rather than one answer. A prompt like give me three subject lines for this email, then tell me which you would pick gets better results than asking for the answer outright.
Is ChatGPT Safe to Use?
Generally yes, when used responsibly. A few habits keep you on the right side of the risks:
Do not share sensitive personal information such as passwords, bank details or medical records.
ChatGPT can make mistakes, so always verify important facts before you rely on them.
On free and Plus plans, OpenAI may use your conversations to improve its models. Teams and Enterprise plans opt out by default.
ChatGPT is not a doctor, a lawyer or a financial adviser. For high-stakes decisions, use a qualified professional.
Treated as a capable assistant whose work you check, ChatGPT is a safe and useful tool. Treated as an oracle, it will eventually embarrass you.
What Are the Limitations of ChatGPT?
Every user should know about four limitations:
**Hallucinations.** ChatGPT can sound confident while being completely wrong, including inventing sources, quotes and statistics. Always check facts against an authoritative source.
**Knowledge cut-off.** Its training data stops at a certain date, although on paid plans it can search the web for current information.
**Bias.** It was trained on internet text, which contains human biases. Outputs can reflect those biases.
**It is not a search engine.** By default it does not retrieve live web pages. It generates responses from patterns, not lookups, unless web search is switched on.
None of these make ChatGPT a bad tool. They make it a tool worth understanding, which is the whole reason this site exists.
ChatGPT vs Google: What's the Difference?
Google and ChatGPT solve different problems, and the difference matters:
Google retrieves and ranks web pages. ChatGPT generates a direct answer.
Google shows you its sources by default. ChatGPT does not always cite sources, although it can.
ChatGPT can write and create things. Google cannot.
Google is better for breaking news and fact-checking. ChatGPT is better for explaining concepts, drafting content and working through problems.
The line has blurred since ChatGPT Search launched in October 2024, because ChatGPT can now search the web and cite what it finds. In practice most people use both: Google for finding and verifying, ChatGPT for thinking and making. If you are weighing up AI assistants against each other, our ChatGPT vs Gemini comparison, our ChatGPT vs Claude comparison and our ChatGPT vs Copilot comparison cover the most popular alternatives in detail.
What Is the Latest Version of ChatGPT?
As of October 2026, ChatGPT runs on GPT-6 Astra as its most capable model. Free users have access to GPT-6 Luna, Plus users get GPT-6 Sol, and Pro users get GPT-6 Astra. GPT-6 Astra became the stable release on 25 September 2026. OpenAI updates its models regularly, so visit chatgpt.com/pricing to see the current model lineup by plan.
Frequently Asked Questions About ChatGPT
What is ChatGPT?
ChatGPT is an AI chatbot developed by OpenAI. It understands natural language and generates human-like responses to questions, writing requests, code tasks and more. It uses a large language model called GPT, short for Generative Pre-trained Transformer, to predict and generate text.
Is ChatGPT free to use?
Yes. ChatGPT offers a free version with access to the GPT-6 Luna model. Paid plans, including Plus and Pro, provide access to more powerful models, higher usage limits, image generation and advanced features.
What does GPT stand for in ChatGPT?
GPT stands for Generative Pre-trained Transformer. Generative means it creates new content, pre-trained means it learned from a large dataset before you use it, and transformer refers to the type of neural network architecture it is built on.
Who made ChatGPT?
ChatGPT was made by OpenAI, an AI research company founded in 2015. The current CEO is Sam Altman. Microsoft has invested at least $13 billion in OpenAI and powers much of its infrastructure through Azure.
Is ChatGPT safe?
ChatGPT is generally safe to use when used responsibly. Avoid sharing sensitive personal information, and always verify important facts independently. For high-stakes decisions involving health, law or finances, consult a qualified professional rather than relying on ChatGPT.
Can ChatGPT replace Google?
Not entirely. ChatGPT is better at explaining concepts, writing and problem-solving. Google is better at retrieving current information, news and specific web pages. Many people now use both: ChatGPT for tasks that need a written answer or creative work, and Google for finding and verifying facts.
How do I start using ChatGPT?
Go to chatgpt.com and create a free account. Type your question or request in the message box and press Enter. ChatGPT will respond immediately, and you can follow up with more messages to refine the answer or change direction.
What is the current version of ChatGPT?
As of October 2026, ChatGPT runs on GPT-6 Astra for Pro users. Free users access GPT-6 Luna, and Plus users access GPT-6 Sol. OpenAI updates these models regularly.
The Bottom Line
ChatGPT is an AI chatbot from OpenAI that understands plain English and answers questions, writes content, generates images and helps with code. In 2026 it is the most-used AI tool in the world, and the free plan is enough for most people to find out why.
The technology will keep changing, and this guide will keep up with it. Explore more ChatGPT guides at whatischatgpt.co.uk.
References and Further Reading
Sources used in this guide:
OpenAI: Introducing ChatGPT, the original launch announcement.
Wikipedia: ChatGPT, a comprehensive reference with full history.
IBM Think: What is ChatGPT?, a technical explanation of how it works.
