About Apertus

Apertus is Switzerland’s first large-scale, fully open, multilingual language model. Developed by researchers at ETH Zurich, EPFL, and the Swiss National Supercomputing Centre (CSCS), it represents a new approach to foundation model development: built by public institutions, designed for the public good.

The name comes from the Latin word for “open” — reflecting the model’s defining characteristic. Unlike commercial models developed behind closed doors, Apertus makes its architecture, weights, training data, and methods fully accessible. Please visit the Frequently Asked Questions and our Documentation section for details. Use the Contact page to share ideas and questions with the Apertus team.

Swiss AI Initiative

The Swiss AI Initiative is a national research effort to build capabilities for advanced, trustworthy AI systems for the benefit of society. Launched in December 2023, it is co-led by ETH Zurich and EPFL. Apertus is one of several projects within the Initiative, which spans research in foundation models, AI safety, applications, and education.

The Initiative represents one of the world’s largest open science efforts dedicated to AI foundation models. It pursues an open science approach to increase transparency and access for startups, SMEs, large companies, and the public sector in Switzerland and beyond. Please visit swiss-ai.org to learn more.

We are grateful to the support of all our strategic partners, members, and community.