OpenAI Blog

GPT-2: 1.5B release

As the final model release of GPT-2’s staged release, we’re releasing the largest version (1. 5B parameters) of GPT-2 along with code and model weights to facilitate detection of outputs of GPT-2 models.

OpenAI Blog
Aug 20, 2019

GPT-2: 6-month follow-up

We’re releasing the 774 million parameter GPT-2 language model after the release of our small 124M model in February, staged release of our medium 355M model in May, and subsequent research with partners and the AI community into the model’s potential for misuse and societal benefit. We’re also releasing an open-source legal agreement to make it easier for organizations to initiate model-sharing partnerships with each other, and are publishing a technical report about our experience in coordinating with the wider AI research community on publication norms.

OpenAI Blog
Apr 14, 2025

Introducing GPT-4.1 in the API

Introducing GPT-4. 1 in the API—a new family of models with across-the-board improvements, including major gains in coding, instruction following, and long-context understanding.

OpenAI Blog
Apr 23

Introducing GPT-5.5

Introducing GPT-5. 5, our smartest model yet—faster, more capable, and built for complex tasks like coding, research, and data analysis across tools.