Apertus – Open Foundation Model for Sovereign AI
Apertus is a fully open foundation model developed by the Swiss AI Initiative, a collaboration between EPFL, ETH Zurich, and CSCS. It offers open weights, open data, and open science, complies with the EU AI Act, supports 1000+ languages, and competes with top open models at 8B and 70B scales.
Fully Open Foundation Model for Sovereign AI
Developed by the Swiss AI Initiative as a collaborative effort between EPFL, ETH Zurich, and CSCS. Open weights, open data, open science.
Get Started Technical Information
Fully Open
Training data, code, weights, methods, and alignment principles — all documented and reproducible. Apertus is to AI as Open is to Source.
Compliant at Scale
Built to meet EU AI Act requirements: the model respects opt-outs, removes PII, 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.
Swisscom is a Strategic Partner of the Swiss AI Initiative.
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Our newsletter will keep you on top of Apertus releases, our team's research, and community news.
Jun 15
Apertus Mini
A set of 16 small language models released to demonstrate distillation and quantization techniques.
Apr 25
Apertus paper at ACL 2026
Our technical report has been accepted at a leading conference for AI & NLP.
Mar 17
Apertus for Ticino
Fine-tuned model powers in-house AI translation
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