GPT-2 is a pretrained transformer-based language model developed by OpenAI for generating natural language text. Trained on 40GB of internet data from outbound Reddit links (excluding Wikipedia), it uses causal language modeling to predict the next token in a sequence. The model was trained without human labels and learns representations of English that support text generation, feature extraction, and fine-tuning. GPT-2 uses a byte-level BPE tokenizer with a vocabulary of 50,257 and handles sequences up to 1024 tokens. It’s the smallest of the GPT-2 family with 124 million parameters and can be used with Hugging Face's Transformers in PyTorch, TensorFlow, and JAX. Though widely used, it reflects biases from its training data and is not suitable for factual tasks or sensitive deployments without further scrutiny. Despite limitations, GPT-2 remains a foundational model for generative NLP tasks and research.
Features
- 124 million parameter autoregressive transformer
- Trained on Reddit-linked web pages (WebText corpus)
- Generates coherent English text from prompts
- Compatible with PyTorch, TensorFlow, JAX, and ONNX
- Byte-level BPE tokenization with 50,257 tokens
- Zero-shot performance on multiple language benchmarks
- Easily integrated via Hugging Face pipelines
- Known for bias and lack of fact-checking mechanisms