Choosing a file format

Person on computer

All digital file formats are in danger of becoming outdated. If that happens, future software may not be able to read or show the information in the files correctly. To minimise the risk that files become unreadable, you should choose a file format that is likely to be usable in the future. As a general guideline, file formats best suited for long-term preservation and accessibility:

  • are commonly used
  • can be read by multiple software
  • are well-documented, meaning that it is possible to find a technical specification which details how information is stored in the format
  • are open/non-proprietary.

You can read more about how to manage and choose file formats in the File format section on our Data Management pages.

More information about digital formats can also be found on the Library of Congress website:

File formats for long-term preservation of data

To help you figure out whether a certain format complies with these criteria, SND has created a list of suggested file formats that are suitable for long-term preservation of research data. Note that this is not a complete list of formats and it will change as technical circumstances change. It's also possible that other file formats are better suited for research data in your field of research.

Recommended formats are those that SND considers having the highest probability to maintain accessibility and readability in the future.

Accepted formats are commonly used formats that have good prospects of remaining readable in the long term. 

Read more about file formats for different types of data in SND's guides to best practice. Click the links below to open each guide. Note that these guides are available in Swedish only. 


Recommended formats

Accepted formats

Text documents

  • ASCII (.txt)
  • MS Word (.docx)
  • OpenDocument Text (.odt)
  • PDF/A (.pdf)
  • Unicode (.txt)
  • MS Word (.doc)
  • PDF (.pdf)
  • Rich Text Format (.rtf)

Markup language

  • HTML (.html)
  • JSON (.json)
  • XML (.xml)
  • SGML (.sgml)
  • Markdown (.md) 


  • CSV (.csv)
  • MS Excel (.xlsx)
  • OpenDocument Spreadsheet (.ods)
  • TSV (.tsv)
  • MS Excel (.xls)
  • OOXML (.docx, .docm)
  • PDF/A (.pdf)


  • CSV (.csv)
  • SIARD (.siard)
  • SQL (.sql)
  • dBase III or IV (.dbf)
  • Filemaker Pro (.fmp7, .fmp12)
  • MS Access (.mdb, .accdb)
  • OpenDocument Base (.odb)

Statistical data

  • OpenDocument (.ods)
  • SPSS portable (.por)
  • SPSS SAV (.sav)
  • STATA (.dta)
  • CSV (.csv)
  • MS Excel (.xls, .xlsx)
  • R (.rdata, .rda)
  • SAS (.sas)
  • SAS transport (.xpt)


  • Adobe Digital Negative format (.dng)
  • DICOM (.dcm)
  • PNG (.png)
  • TIFF (.tif, .tiff)
  • Adobe Photoshop document file (.psd)
  • JPEG (.jpg, .jpeg)
  • JPEG 2000 (.jp2, .jpx)
  • Raw image data (various formats)

Image (vector)

  • SVG (.svg)
  • Adobe Illustrator (.ai)
  • AutoCAD Drawing Interchange Format (.dxf)
  • EPS (.eps)
  • PDF/A (.pdf)
  • PDF (.pdf)
  • WebCGM 2.1 (.cgm)


  • Lossless AVI (.avi)
  • Matroska (.mkv)
  • MPEG-1 (.mpg, .mpeg, …)
  • MPEG-2 (.mpg, .mpeg, …)
  • MPEG-4 H.264 (.mp4)
  • MPEG-4 Part 14/MP4 (.mp4)
  • Audio Video Interleave (.avi)
  • DivX (.divx)
  • MXF (.mxf)
  • Motion Jpeg 2000 (.mj2, .mjp2)
  • QuickTime (.mov)


  • AIFF (.aif, .aiff)
  • Broadcast Wave Format (.bwf)
  • FLAC (.flac)
  • Matroska (.mka)
  • MPEG-1 (.mpg, .mpeg, …)
  • MPEG-2 (.mpg, .mpeg, …)
  • Waveform Audio (.wav)
  • AAC (.aac)
  • Audio Video Interleave (.avi)
  • MP3 (.mp3)
  • MPEG-4 Part 14/MP4 (.mp4)
  • Ogg Vorbis (.ogg)
  • Opus (.opus)
  • Speex (.speex)

Geographical information (GIS)

  • CSV (.csv)
  • Digital Elevation Model (DEM) Format (.dem)
  • Geographic Markup Language (.gml)
  • GeoJSON (.geojson)
  • GeoTIFF (.tif, .tiff)
  • Keyhole Markup Language (.kml)
  • NetDCF (.nc)
  • OGC GeoPackage (.gpkg)
  • ArcInfo Interchange (.e00)
  • ESRI GRID (.adf, .asc, .grd)
  • ESRI Shapefile (.shp)
  • LAS (LASer) File Format
  • MapInfo (.tab, .dat)
  • MapInfo Interchange Format (.mif, .mid)


  • W3C standards


3D data

  • COLLADA (.dae)
  • CSV (.csv)
  • NetDCF (.nc)
  • Universal 3D (.u3d)
  • Wavefront OBJ file (.obj)
  • X3D (.x3d)
  • 3DS (.3ds)
  • AutoCAD Drawing Interchange Format (.dxf)
  • Autodesk 3D asset exchange format (.fbx)
  • Stanford polygon file format (.ply)
  • STL 2.0 (.stl)
  • Virtual Reality Modelling Language (.vrml)