From ETH Zurich to Swisscom: Apertus marks the birth of Switzerland’s first large open-source language model — a European signal for transparency, research, and digital sovereignty.
An Open Countermodel to the AI Powerhouses
While the global spotlight shines on the major U.S. tech companies — OpenAI, Anthropic, Google, and Meta — a remarkable alternative is taking shape in Switzerland: Apertus. Unveiled in 2025, this large language model is not only the first of its kind developed in Switzerland but also one of the most transparent AI initiatives worldwide. At its core lies a bold vision: artificial intelligence as a public good, not a closed commercial product.
A Collaboration Between ETH, EPFL, and Swisscom
Apertus is the result of a collaboration among Switzerland’s leading research and technology institutions:
- ETH Zurich and EPFL Lausanne lead the scientific development.
- The Swiss National Supercomputing Centre (CSCS) in Lugano provides the computational power via its Alps supercomputer.
- Swisscom integrates the model into its Swiss AI Platform, bringing it to enterprise clients.
This combination of academic excellence and industrial application makes Apertus a showcase of applied AI innovation in Europe.
Technical Foundation: GPT-Like, but with Swiss Precision
Apertus is built on the transformer architecture, similar to the GPT family of models. Two versions have been released:
- a model with 8 billion parameters, and
- a larger one with 70 billion parameters,
each available in instruction-tuned variants optimized for conversational use.
The training corpus consists of about 15 trillion tokens across more than a thousand languages. Special attention was given to underrepresented languages such as Swiss German and Romansh.
A custom embedding system was designed to prevent English from dominating the dataset — a frequent bias in global AI models.
Transparency as a Principle
What truly distinguishes Apertus is its radical openness.
The entire training process, source code, and datasets have been made public — an unprecedented level of transparency among large-scale language models.
This makes Apertus fully compliant with the EU AI Act’s transparency requirements and sets a new standard for responsible AI development.
Researchers, developers, and companies can trace exactly how and with what data the model was trained.
It’s not just a technical decision — it’s a political statement about accountability and democratic oversight in artificial intelligence.
Data Protection and Ethical Boundaries
The project’s creators emphasize that development followed Swiss data protection and copyright laws.
At the same time, they openly acknowledge that not every textual source used in training was formally licensed — a transparency that reflects intellectual honesty rather than negligence.
Apertus thus navigates the realistic gray zone that many AI research projects inhabit, where the ideals of openness intersect with the complex realities of digital content rights.
Not Yet a Chatbot — but a Powerful Foundation
As of autumn 2025, Apertus exists purely as a text-based model.
It does not yet support multimodal capabilities such as image, video, or audio processing. However, the development roadmap envisions extensions that could eventually make Apertus a fully fledged open-source assistant.
Even today, the model serves as a robust foundation for specialized AI applications in research, public administration, and industry.
Why Apertus Matters
Apertus is more than a research project — it is a message to Europe.
At a time when AI infrastructure is increasingly concentrated in private hands, Switzerland demonstrates that technological sovereignty and openness can coexist.
The benefits are clear:
- Independence from U.S. platforms
- Compliance with European data protection standards
- Promotion of multilingual and local innovation
In this sense, Apertus stands as a symbol of an independent European AI strategy — small, precise, and transparent.
Conclusion: Apertus as a Blueprint for Open AI
With Apertus, ETH, EPFL, and Swisscom have set a new benchmark:
a powerful, auditable, and freely accessible language model designed to serve science, business, and society alike.
In a world where many AI systems operate as opaque “black boxes,” Switzerland’s Apertus — true to its Latin name meaning “open” — offers a window into a transparent, verifiable AI future.
https://de.wikipedia.org/wiki/Apertus