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GPT meaning: what GPT stands for, and how to find ChatGPT
Looking for ChatGPT? The official site is chatgpt.com, and the official apps are called ChatGPT in the App Store and Google Play. If you typed GPT because you wanted to know what it means, it stands for Generative Pre-trained Transformer: the family of AI models that OpenAI builds and that ChatGPT runs on.
This guide explains each word in plain English, the difference between GPT and ChatGPT, how to reach the real ChatGPT safely, and how the GPT models got from GPT-1 to today’s GPT-6.
GPT meaning: what each word stands for
| Word | What it means |
|---|---|
| Generative | It generates, meaning it creates new text, one piece at a time, instead of only sorting or labelling |
| Pre-trained | It first learns from a huge amount of text, before being tuned for particular jobs |
| Transformer | The kind of neural network it is built on, which weighs how the words in a passage relate to each other |
The idea came together in 2018. OpenAI’s first GPT paper described its approach as a combination of two existing ideas: the Transformer, and unsupervised pre-training on large amounts of text. The Transformer itself came from a 2017 paper by Google researchers, Attention Is All You Need.
In practice, a GPT model predicts what text should come next, based on patterns it learnt. That is why it writes fluently, and also why it can confidently state things that are wrong.
GPT vs ChatGPT: the model and the app
GPT is the engine; ChatGPT is the car. The GPT models are the AI systems themselves. ChatGPT is OpenAI’s app that lets you chat with them, launched on 30 November 2022. The ChatGPT meaning is simply chat plus GPT.
OpenAI also sells its GPT models to other businesses through its API. OpenAI says GPT-6 Astra, for example, is available through the OpenAI API, Microsoft Azure and AWS Bedrock as well as in ChatGPT. So an app built by another company may use GPT inside it without being ChatGPT.
GPT chat: how to reach the official ChatGPT safely
If you want GPT chat, use only these:
- Web: chatgpt.com
- iPhone and iPad: the App Store listing called ChatGPT, published by OpenAI OpCo, LLC
- Android: the Google Play listing called ChatGPT, with OpenAI as the developer
- Windows and Mac: chatgpt.com/download
Look-alike sites are a real risk. In May 2026 Malwarebytes reported a fake ChatGPT download site that copied OpenAI’s download page and installed password-stealing malware on Windows and Mac computers. Type the address yourself rather than clicking search ads, and check the developer name before you install an app.
New to it? Our guide on how to use ChatGPT walks through your first prompts, and our ChatGPT free vs paid guide compares the rand prices.
A short history of GPT
| Date | Release | What changed |
|---|---|---|
| 11 June 2018 | GPT-1 | OpenAI shows that a pre-trained Transformer can be tuned for many language tasks |
| 14 February 2019 | GPT-2 | A much larger model that writes realistic, coherent text on a topic |
| 28 May 2020 | GPT-3 | A far larger model that could do new tasks from a few examples in the prompt |
| 30 November 2022 | ChatGPT | The chat app that made GPT a household name |
| 14 March 2023 | GPT-4 | A more capable model that could also read images |
| 13 May 2024 | GPT-4o | One model handling text, audio and images in real time |
| 7 August 2025 | GPT-5 | OpenAI’s smartest model at the time, with thinking built in |
| July 2026 | GPT-5.6 | GPT-5.6 Sol becomes ChatGPT’s flagship reasoning model on paid plans |
| 3 September 2026 | GPT-6 Astra | OpenAI’s most capable model to date |
| 22 September 2026 | GPT-6 Sol and Luna | Faster, cheaper GPT-6 models trained with methods similar to Astra |
Today’s GPT models, in plain words
- GPT-6 Astra is OpenAI’s most capable model. OpenAI said it would reach ChatGPT Plus, Pro, Business and Enterprise users, as well as the API.
- GPT-6 Sol and GPT-6 Luna bring GPT-6 methods to faster, cheaper models. In ChatGPT, OpenAI says they are used in ChatGPT Work and Codex rather than in regular chats.
- GPT-5.6 Luna is the model behind the free plan’s unlimited everyday chats, according to ChatGPT’s pricing page.
For how today’s models compare, including GPT against its rivals, Zaiq’s benchmark sets it out in plain English.
GPT used loosely for any chatbot
Many people now say GPT to mean any AI chatbot, the way some people say Google for any search. Strictly, GPT refers only to OpenAI’s models. Claude from Anthropic, Gemini from Google and DeepSeek’s models are separate families built by other companies, even though they do similar things.
GPTs: custom assistants inside ChatGPT
GPTs, also called custom GPTs, are versions of ChatGPT set up for a single purpose. According to OpenAI, a GPT can combine its own instructions, uploaded files and selected tools, such as web search or image creation.
Two recent changes matter. OpenAI says new GPTs can no longer be created on personal plans, including Free, Go, Plus and Pro, although existing GPTs still work. It also plans to retire custom GPTs in favour of Plugins, starting with Enterprise workspaces on 11 December 2026, with other plans expected to follow the same timeline.
Related guides
Questions people ask
What does GPT stand for?
GPT stands for Generative Pre-trained Transformer. Generative means it creates new text, pre-trained means it first learnt from a huge amount of text before being tuned for tasks, and Transformer is the type of neural network it uses, first described by Google researchers in 2017. OpenAI's GPT models power ChatGPT.
What is the difference between GPT and ChatGPT?
GPT is the family of AI models, the engine. ChatGPT is OpenAI's app that you chat with, launched on 30 November 2022, which runs on those models. The name ChatGPT simply joins chat and GPT. OpenAI also sells access to its GPT models to other companies through its API, so GPT can power other apps too.
Where do I find GPT chat?
The official ChatGPT is at chatgpt.com. On a phone, install ChatGPT from the App Store, where the publisher is OpenAI OpCo, LLC, or from Google Play, where the developer is OpenAI. For Windows and Mac, use chatgpt.com/download. Avoid download links in search ads and look-alike apps from other developers.
What is the latest GPT model?
GPT-6. OpenAI introduced GPT-6 Astra, its most capable model, on 3 September 2026, and added the faster, cheaper GPT-6 Sol and GPT-6 Luna on 22 September 2026. Before that came the GPT-5 family, starting with GPT-5 in August 2025 and ending with GPT-5.6 in July 2026.
Is GPT free to use?
You can use GPT models free through ChatGPT's free plan, which OpenAI says gives unlimited everyday text chats with GPT-5.6 Luna, within abuse limits. The newest GPT-6 models need a paid plan, such as Plus at R399 a month in South Africa, or pay-per-use access through OpenAI's API.
What are GPTs in ChatGPT?
GPTs, or custom GPTs, are versions of ChatGPT set up for one purpose, with their own instructions, files and tools. You can still use existing GPTs, but new ones cannot be created on personal plans, and OpenAI plans to retire custom GPTs in favour of Plugins, starting with Enterprise workspaces on 11 December 2026.
Sources
- OpenAI: Improving language understanding with unsupervised learning (GPT-1, 11 June 2018)
- OpenAI: Better language models and their implications (GPT-2, 14 February 2019)
- OpenAI: Language models are few-shot learners (GPT-3, 28 May 2020)
- OpenAI: Introducing ChatGPT (30 November 2022)
- OpenAI: GPT-4 (14 March 2023)
- OpenAI: Hello GPT-4o (13 May 2024)
- OpenAI: Introducing GPT-5 (7 August 2025)
- OpenAI: GPT-5.6 (July 2026)
- OpenAI: GPT-6 Astra (3 September 2026)
- OpenAI: Introducing GPT-6 Sol and Luna (22 September 2026)
- OpenAI Help Center: Model release notes
- OpenAI Help Center: ChatGPT Work and Codex
- OpenAI Help Center: GPTs in ChatGPT
- ChatGPT pricing (OpenAI)
- Download ChatGPT (OpenAI)
- ChatGPT on the App Store, South Africa
- Attention Is All You Need (Vaswani and others, arXiv, June 2017)
- What is GPT (generative pretrained transformer)? (IBM)
- Fake ChatGPT download site infects Windows and Mac users with malware (Malwarebytes)
Checked September 2026. Prices and features change, so confirm on the official site before you buy.