GPT models are used in ChatGPT and countless other AI chatbots and agents. Following are the various versions from OpenAI.
GPT Models (1, 2, 3, 4, 4t, 4o)
Launched in 2018, GPT-1 was fed over 100 million examples. A year later, GPT-2 was trained on more than a billion. Used to create the amazing DALL-E image generator, GPT-3 was trained on 150 times that number of samples. See
DALL-E.
In late 2022, ChatGPT was built on GPT-3.5, and GPT-4 came out four months later. Instead of being trained on only text, GPT-4 accepts both text and images. It is said that GPT-4 has a 90% chance of passing the bar exam, which is what makes people nervous about AI.
GPT-4, 5 and 6
The GPT-4 family was a huge breakthrough in human-like intelligence. Everyone trying GPT-4 came away amazed. GPT-4 Turbo (GPT-4t) was faster and more efficient, and multimodal GPT-4 Omni (GPT-4o) supports text, audio and images.
Released in 2025, GPT-5 strengthened reasoning and was released in several versions (see
GPT-5), and GPT-6 made improvements in handling complex problems (see
GPT-6 Astra).