OpenAI‘s ChatGPT is leading the way in the generative AI revolution, quickly attracting millions of users, and promising to change the way we create and work. In many ways, this feels like another iPhone moment, as a new product makes a momentous difference to the technology landscape.
The AI bot, developed by OpenAI and based on a Large Language Model (or LLM), continues to grow in terms of its scope and its intelligence. Here we’re going to cover everything you need to know about ChatGPT, from how it works, to whether or not it’s worth you paying for the premium version.
If you’re wondering what ChatGPT is, and what it can do for you, then you’re in exactly the right place. For those of you who are just getting started with the tech, we’d also recommend our guide to how to use ChatGPT, which introduces a few ways to get the most out of the software immediately.
You’ll have noticed that ChatGPT has sparked something of an AI arms race, with Microsoft building Copilot using similar technology, Google launching its own Google Gemini apps, social media apps such as Snapchat introducing AI chatbots of their own, and X (formerly Twitter) getting in on the act with its Grok AI.
What is ChatGPT?
ChatGPT is an AI chatbot that was initially built on a family of Large Language Models (or LLMs), collectively known as GPT-3. OpenAI has now announced that its next-gen GPT-4 models are available, models that can understand and generate human-like answers to text prompts, because they’ve been trained on huge amounts of data.
For example, ChatGPT’s most original GPT-3.5 model was trained on 570GB of text data from the internet, which OpenAI says included books, articles, websites, and even social media. Because it’s been trained on hundreds of billions of words, ChatGPT can create responses that make it seem like, in its own words, “a friendly and intelligent robot”.
OpenAI’s current flagship model, ChatGPT-4o (the o is for “omni”), can work across any combination of text, audio and images meaning many more applications for AI are now possible. ChatGPT-4o is also much faster at processing than previous versions, especially with audio, meaning that responses to your questions can feel like you are chatting to a person in real time.
This ability to produce human-like, and frequently accurate, responses to a vast range of questions is why ChatGPT became the fastest-growing app of all time, reaching 100 million users in only two months. The fact that it can also generate essays, articles, and poetry has only added to its appeal (and controversy, in areas like education).
But early users have also revealed some of ChatGPT’s limitations. OpenAI says that its responses “may be inaccurate, untruthful, and otherwise misleading at times”. OpenAI CEO Sam Altman also admitted in December 2022 that the AI chatbot is “incredibly limited” and that “it’s a mistake to be relying on it for anything important right now”.
Still, the world is currently having a ball exploring ChatGPT and, despite the arrival of a paid ChatGPT Plus version for $20 (about £16 / AU$30) a month, you can still use it for free too, on desktop and mobile devices.
What does ChatGPT stand for?
ChatGPT stands for “Chat Generative Pre-trained Transformer”, which is a bit of a mouthful. Let’s take a look at each of those words in turn.
The ‘chat’ naturally refers to the chatbot front-end that OpenAI has built for its GPT language model. The second and third words show that this model was created using ‘generative pre-training’, which means it’s been trained on huge amounts of text data to predict the next word in a given sequence.
Lastly, there’s the ‘transformer’ architecture, the type of neural network ChatGPT is based on. Interestingly, this transformer architecture was actually developed by Google researchers in 2017 and is particularly well-suited to natural language processing tasks, like answering questions or generating text.
Google was only too keen to point out its role in developing the technology during its announcement of Google Bard. But ChatGPT was the AI chatbot that took the concept mainstream, earning it another multi-billion investment from Microsoft, which said that it was as important as the invention of the PC and the internet.
When was ChatGPT released?
ChatGPT was released as a “research preview” on November 30, 2022. A blog post casually introduced the AI chatbot to the world, with OpenAI stating that “we’ve trained a model called ChatGPT which interacts in a conversational way”.
The interface was, as it is now, a simple text box that allowed users to answer follow-up questions. OpenAI said that the dialog format, which you can now see in the Bing search engine and many other places, allows ChatGPT to “admit its mistakes, challenge incorrect premises, and reject inappropriate requests”.
A more advanced GPT-4o model was released on May 13 2024 to all users, not just ChatGPT Plus subscribers, while the ChatGPT 3.5 model remains available as well.
Going back into the mists of time, OpenAI did also previously release earlier GPT models in limited form – its GPT-2 language model, for example, was announced in February 2019, but the company said it wouldn’t release the fully-trained model “due to our concerns about malicious applications of the technology”.
OpenAI also released a larger and more capable model, called GPT-3, in June 2020, but it was the full arrival of ChatGPT 3.5 in November 2022 that saw the technology burst into the mainstream. Throughout the course of 2023, it got several significant updates too, which made it easier to use.
How much does ChatGPT cost?
ChatGPT is still available to use for free, but now also has a paid tier. After growing rumors of a ChatGPT Professional tier, OpenAI said in February that it was introducing a “pilot subscription plan” called ChatGPT Plus in the US. A week later, it made the subscription tier available to the rest of the world.
ChatGPT Plus costs $20 p/month (around £16 / AU$30) and brings many benefits over the free tier. It promises to give you full access to ChatGPT even during peak times, which is when you’ll otherwise frequently see “ChatGPT is at capacity right now” messages during down times.
OpenAI says the ChatGPT Plus subscribers also get “faster response times”, which means you should get answers around three times quicker than the free version (although this is no slouch). And the final benefit is “priority access to new features and improvements”, like the experimental ‘Turbo’ mode that boosts response times even further.
It isn’t clear how long OpenAI will keep its free ChatGPT tier, but the current signs are promising. The company says “we love our free users and will continue to offer free access to ChatGPT”. Right now, the subscription is apparently helping to support free access to ChatGPT. Whether that’s something that continues long-term is another matter.
It certainly seems that ChatGPT Plus has proved to be a popular option – new sign-ups were briefly paused in November 2023 so that OpenAI could cope with the increase in demand it was seeing.
How does ChatGPT work?
ChatGPT has been created with one main objective – to predict the next word in a sentence, based on what’s typically happened in the gigabytes of text data that it’s been trained on. It’s sort of like a super-advanced autocorrect.
Once you give ChatGPT a question or prompt, it passes through the AI model and the chatbot produces a response based on the information you’ve given and how that fits into its vast amount of training data. It’s during this training that ChatGPT has learned what word, or sequence of words, typically follows the last one in a given context.
For a long deep dive into this process, we recommend setting aside a few hours to read this blog post from Stephen Wolfram (creator of the Wolfram Alpha search engine), which goes under the bonnet of ‘large language models’ like ChatGPT to take a peek at their inner workings.
But the short answer? ChatGPT works thanks to a combination of deep learning algorithms, a dash of natural language processing, and a generous dollop of generative pre-training, which all combine to help it produce disarmingly human-like responses to text questions. Even if all it’s ultimately been trained to do is fill in the next word, based on its experience of being the world’s most voracious reader.
It does sometimes go a little bit crazy, and OpenAI has been honest about the ‘hallucinations’ that ChatGPT can have, and the problems inherent in these LLMs. Be wary of relying completely on anything ChatGPT says.
What can you use ChatGPT for?
ChatGPT has been trained on a vast amount of text covering a huge range of subjects, so its possibilities are nearly endless. But in its early days, users have discovered several particularly useful ways to use the AI helper.
Broadly speaking, these can be divided into natural language tasks and coding assistance. In our guide to six exciting ways to use ChatGPT, we showed how you can use it for drafting letters, writing poetry, and creating (or adapting) fiction. That said, it does still have its limitations, as we found when ChatGPT showed us just how far it is from writing a blockbuster movie.
That hasn’t stopped self-publishing authors from embracing the tech, though. With YouTube and Reddit forums packed with tutorials on how to write a novel using the AI tech, the Amazon Kindle store is already on the cusp of being overrun with ChatGPT-authored books.