LLMOpen weights
GPT-1
OpenAI
Updated May 21, 2026 · Benchmarks via Artificial Analysis, specs & pricing via OpenRouter · Methodology · Report an error
Superseded by GPT-2
Specifications
- Type
- LLM
- Access
- Open weights
- Released
- June 11, 2018
- Parameters
- 117M
- Context window
- 512 tokens
- Input
- Text
- Output
- Text
Our take
The first GPT: a Transformer decoder pretrained on unlabeled text then fine-tuned per task. It introduced the generative pretraining recipe that everything since builds on.