File formats for your data

Making informed file format decisions can help ensure long-term accessibility to your research data. The file format you use for collecting and storing data is an important component of planning for data management

What is a file format?

A file format is a way of saving information in the form of a computer file. The file format type will depend on what type of data is being saved, as well as what type of program is used to save or open the file. 

Choosing a file format

When choosing a file format to save your data, it is important to consider how accessible the data file will be for other users in the future.

Some file formats are developed specifically for certain programs (such as the .psd format for Adobe Photoshop, or the .sav format for SPSS Statistics). This puts restrictions on the type of programs that can open these file types, as the original software developer controls whether the programs required to open these files will still be supported in future. For these reasons, more open and widely supported file formats are recommended for saving research data. Some key file format characteristics to look for are:

  • Complete and open documentation about the format
  • Platform independence, non-proprietary (e.g. not a file that can only be opened in either Windows or Mac)
  • Minimal embedded content (for example, video and images are stored separately from documents rather than embedded in them)
  • Wide adoption -- common programs and formats are better
  • No password protection on the individual files themselves

For more information about file format selection guidelines, refer to these recommended file formats for different data types, or see the complete Library of Congress list of digital file formats with details on the sustainability of each type. 

Additional resources

Library of Congress Recommended Formats Statement 2022
List of file formats with characteristics that allow for long-term preservation and continued accessibility.

File formats - UK Data Service
Considerations for choosing file formats, and an overview of recommended research data file formats.