Model Family
aka Generative Pre-trained Transformer
GPT
OpenAI's flagship language model family, decoder-only transformers from GPT-1 to GPT-5.
Definition
The GPT line pioneered scaled decoder-only transformers, evolving from GPT-1 (117M parameters) to multimodal frontier systems. Each generation introduced new capabilities — instruction following (GPT-3.5), vision (GPT-4), reasoning (o-series). GPT models are the most widely deployed LLMs.
Common use cases
- Chat
- Code
- Reasoning