Developed by the Swiss AI Initiative as a collaborative effort between EPFL, ETH Zurich, and CSCS. Open weights, open data, open science.
Fully Open
Training data, code, weights, methods, and alignment principles: all documented and reproducible. Apertus is to AI as Open is to Source.
Responsible at Scale
Developed with the EU AI Act in mind: the model respects opt-outs, removes PII, and prevents memorization. A global foundation to build on.
Run for Performance
Competitive with top open models at an equivalent scale of 8B and 70B parameters. Multilingual from day one, trained on 1000+ languages.