Leap forward in European Web sovereignty: Horizon Europe funded project “OpenWebSearch.EU” ends after 42 months and puts forth a federated Open Web Index pilot I Media Release

A consortium of 14 research organisations and computing centres have developed and implemented the Open Web Index pilot “OWI” as a fundamental resource for traditional and AI web search applications; overall project results point to strong economic and sovereignty benefits

Passau / Munich — August 2026

The OpenWebSearch.EU consortium announced the successful completion of its 42 months long Horizon Europe funded project, having built and validated a first federated European Open Web Index (OWI). The project results include technical, economic and operational evidence that an Open Web Index can strengthen Europe’s digital sovereignty and support research, innovation and trustworthy AI.

Key achievements:
  • Creation of an operational Open Web Index: ~39 billion URLs crawled across 185 languages, 28 million hosts, producing a 45 TiB web-index from 1.25 PiB of raw data
  • Data availability and tooling for research and R&D, publishing 1,511 public datasets and providing data shards via the OpenWebIndex.eu portal for research use
  • Proof of a federated public–private infrastructure approach that can be scaled with further funding and additional infrastructure partners
  • Commissioned market potential study (MRC, 2024) projecting a net benefit of ~€4.5 billion over 10 years and an expected return on investment within four years of operation
  • Delivery of multiple use case projects on top of the OWI (e.g., OMMS for map POI enrichment)
Challenges and next steps:
  • Current OWI scope does not offer the scale of commercial search indexes; sustainability and scaling remains necessary to broaden commercial and public use.
  • Regulatory and licensing issues make the OWI only available for research purposes currently; for commercial deployment, EU regulatory clarifications are still necessary.
  • Launch of the first search API and an operational frontend is in preparation.
  • Onboarding of additional infrastructure partners and long-term funding to scale the service is needed.
  • The initiative will continue the broader European Open Web Search efforts to push for sustainable and federated operation.
Quotes from the project members:

Michael Granitzer, project coordinator, University of Passau: “An Open Web Index is a foundational public good for research, innovation and sovereign digital services in Europe. The project proves the concept; the next step is scaling and operationalisation with committed public and private partners.”

Megi Sharikadze, Research Manager and Coordinator (BADW-LRZ): “The dedicated and coordinated efforts of the European Open Web Search champions have resulted in the development of the Open Web Index for the Common Good. At a time of growing concerns over digital sovereignty and increasing strategic risks, we are proud that the OpenWebSearch.EU project has delivered a tangible outcome that Europeans can now benefit from. The project has also strengthened collaboration within the Open Web Search Initiative and laid the foundation for broader cooperation with other key stakeholders, including the AI Factories and Antennas of the EuroHPC Joint Undertaking, as well as other high-performance computing and data centres of the Member States.”

Per Öster, Director Corporate Development, CSC: “The OpenWebSearch.EU project has not only demonstrated the feasibility of building an independent, globally comprehensive web index, but also highlighted the significant value of this data for both research and business innovation. At CSC, we are committed to making this resource available as a service for users of the LUMI AI Factory, enabling new opportunities for data-driven research, development, and AI applications.”

Stefan Voigt, Chairman and CEO of Open Search Foundation (OSF): “With the completion of the OpenWebSearch.EU project and the successful proof of the capabilities of a federated Open Web Index, Europe now has a great tool in its hand to grow sovereignty in Web search, analytics and AI.”

Tobias Hecking, German Aerospace Center (DLR): “We have shown the great potential of integrating the Open Web Index with structured access to scientific artifacts for the creation of next generation intelligent information systems for earth sciences and beyond.”

Andreas Wagner, CERN: “Within the OpenWebSearch.EU project, CERN was leading the work package “Federated Data Infrastructure”. We believe that access to the Open Web data is critical for ensuring the transparency, diversity, and openness of the Web. As large search platforms dominate information access, the Open Web Index promotes a decentralised ecosystem that empowers users and smaller organisations to control how information is discovered and shared. This has the potential to foster an exciting future where search is not just a tool for finding information but a force for preserving internet freedom and digital sovereignty.”

Phil Höfer, SUMA-EV: “Europe now has a blueprint for an open web search infrastructure. We hope that this will spur growth in the sector and allow actors in the entire EU to build upon our work.”

Arjen P. de Vries, Radboud University: “We developed the Open Web Index Data Lakes, that let anyone to query the Open Web Indexes remotely, without the need to download all the data first. This is a big step towards open and transparent and web search.”

Christian Gütl and Alexander Nussbaumer, Graz University of Technology: “We have created software components, demonstrators and guidelines that inspire and support others to develop their own trustful and transparent vertical search applications using data from the Open Web Index.”

Jan Martinovič, Head of the Advanced Data Analysis and Simulations Lab, IT4Innovations National Supercomputing Center: “We contributed to the project with high-performance computing infrastructure and technologies such as the LEXIS Platform and iRODS, as well as through our collaboration with European initiatives like EUDAT. Being part of this project also gave us the opportunity to validate our tools in the domain of large-scale web data processing.”

Martin Potthast, Leipzig University: “As a result of the project, we developed some of the fastest web data processing tools available open source. Together with award-winning research results on web analytics, indexing, and retrieval, the project forms a solid foundation for the future of open web search.”

The consortium comprised 14 organisations across 7 countries, including University of Passau, Leibniz Supercomputing Centre (BADW-LRZ), Radboud University, Leipzig University, Graz University of Technology, German Aerospace Center (DLR), IT4Innovations National Supercomputing Center, CERN, Open Search Foundation, A1 Slovenija, CSC – IT Center for Science, NL Net Foundation, SUMA-EV and Webis Group.
The project received funding under Horizon Europe (Grant Agreement No 101070014).

Calls to action 

For researchers, developers and organisations interested in testing or contributing: ows@openwebsearch.eu
Data, publications and code: OWI data shards and project outputs are available via the OpenWebSearch.eu portal and ZENODO repository.

About OpenWebSearch.EU:
OpenWebSearch.EU is the first project the EU has funded to get tomorrow’s web search up and running. It kicked off in September 2022. The 14 partner institutions have been cooperating over a time-frame of three and a half years. The project has received funding of 8.5 million euros from the European Union’s Horizon research and innovation programme under grant agreement no. 101070014.

About Horizon Europe:
Horizon Europe is the EU’s key funding programme for research and innovation. It aims to build a knowledge- and innovation-based society and a competitive economy while contributing to sustainable development. The programme contributes to the implementation of the European Commission’s guidelines.