Different types of research data are acquired, processed, and stored (preserved and/or archived) in different ways, often depending on disciplinary practices. When starting a new project and developing a Data Management Plan (DMP), one of the first key considerations is to decide in advance which file formats will be used. In Horizon Europe recent guide, this decision is explicitly linked to ensuring compliance with FAIR principles (Findable, Accessible, Interoperable, Reusable) and must be clearly described in the DMP as part of the overall data lifecycle planning.

Many proprietary file formats act as “containers” for standard formats, providing additional functionalities tailored to specific software or instruments. While these may facilitate data processing and analysis, they can also limit interoperability and long-term accessibility. Under Horizon Europe requirements, researchers are expected to justify the choice of formats and, where possible, prioritise open, standardised, and interoperable formats to enable data sharing, reuse, and machine-actionability.

In addition, file formats can be either lossless or lossy, depending on whether data compression alters the original content. Lossless formats preserve all original information, while lossy formats reduce file size by removing some data. Although lossy formats may be suitable for analysis or dissemination purposes, they are not always appropriate for long-term preservation. Horizon Europe guidelines emphasises that data should be curated and preserved in a way that maximises reusability, which typically requires retaining raw data or high-quality, non-destructive (lossless) formats.

Did you know? 
A key update compared to Horizon 2020 is that Data Management Plans are now mandatory for all projects generating or reusing data (not only within a pilot), and must be submitted, regularly updated, and treated as a living document throughout the project lifecycle.

Furthermore, Horizon Europe expands the scope of data management beyond datasets to include other research outputs (e.g. software, models, workflows), which must also be considered in terms of formats, standards, and long-term accessibility.

Overall, early decisions on file formats are not only technical but strategic, directly affecting the interoperability, accessibility, and long-term value of research outputs, while ensuring full alignment with Horizon Europe Open Science and FAIR data management requirements.

Did you know? 
FAIR data alone does not guarantee long-term preservation.
While FAIR principles support data management and sharing, they do not fully address the long-term preservation of research data, leaving important gaps in sustainability.

Did you know? 
Data preservation must happen throughout the entire research lifecycle.
Preservation is not just about storing data at the end—it requires continuous actions, planning, and monitoring from creation to long-term access.

As an example, in the biomedical imaging field, a realisation of the huge variety of file formats that exist led to an initiative to make these interoperable. As part of the OMERO project, Bioformats is a software plugin which allows the conversion of multiple established proprietary and standard file formats. Image analysis software such as ImageJ (free and open source) have adopted Bioformats as a plugin to allow users to read and write their image data without having to consider their origin. However, such tools may not always exist for different disciplines, and a researcher should consider storing their acquired data in a standard format at the earliest available opportunity. Many (most?) commercial and open source software packages allow conversion of data into standard formats and this should be exploited.

During the course of the digital revolution, a number of file formats have been recognised to be the file formats of choice for longevity and interoperability.

As an example, the following table describes a variety of file formats for different disciplines that are either recommended or acceptable (from the UK Data Service):

When writing a DMP, researchers are advised to refer to tables such as this to help decide the best file formats to use for their project and to state this clearly.

Video:
Utrecht University. “Preserving research data in the optimal, technically correct way” (How to minimize the risk of losing data. Here you’ll learn which methods there are to preserve your research data in an optimal way)

Publications

• Scaled and automated preservation planning for highly diverse digital collections: the Integrated Preservation Suite. iPres2018: Poster abstract. doi: https://dx.doi.org/10.7207/twr14-02
• Science Europe Guidance Document: Presenting a Framework for Discipline-specific Research Data Management. (January 2018), Science Europe.
• The FAIR Guiding Principles for scientific data management and stewardship. Scientific data, 3, 160018. doi: 10.1038/sdata.2016.18

Other resources

• Best practice for file formats. Stanford Libraries.
• Adapt your Data Management Plan: a list of Data management questions based on the Expert Tour Guide on Data management. Consortium of European Social Sciences Data Archives (CESSDA).
• Expert Tour Guide on Data Management (on section 3 - Process | File formats and data conversion). Consortium of european Social Sciences Data Archives (CESSDA).
• Data management knowledge, tools, and training. DTL - Dutch Techcenter for Life Sciences.
• Digital Preservation Handbook. Digital Preservation Coalition.
• FAIR data: what it means, how we achieve it, and the role of RDA. (presentation from Sarah Jones)
• Storing and Preserving Data. Utrecht University.
• File formats for transfer. The National Archives.
• Format your data: Recommended formats. UK Data Service guidelines.
• Supported formats and Format information. University of Vienna.
• Data Types & File FormatsData Types & File Formats. University of Virginia Library.