File formats

All file formats are in danger of becoming obsolete. If they do, future software may not be able to read or show the information in the files correctly. One way of countering the risks that this poses is to choose file formats that have a high probability of remaining usable in the future. As a general guideline, SND believes that the file formats best suited for long-term sustainability and accessibility:

  • are widely adopted by users
  • are independent of specific software, developers, or vendors
  • have open technical specifications (i.e. are not owned by a single person or organisation)

In practice, it is not always possible to use formats that satisfy all of these criteria. SND has evaluated a number of formats that we consider suitable for the management, long-term preservation, and accessibility of research data. These may change over time due to technical developments.

Preferred formats are those that SND considers to have the greatest chance of maintaining accessibility and readability in the future.

Accepted formats are commonly used formats that have good prospects of being readable in the long term. SND strongly recommends the preferred formats, but will also approve of data in the accepted formats.

Other formats: If you want to deposit data in other formats than those mentioned below, please contact



Preferred 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) 


  • Comma-separated values (.csv)
  • MS Excel (.xlsx)
  • OpenDocument Spreadsheet (.ods)
  • Tab-separated values (.csv)
  • MS Excel (.xls)
  • OOXML (.docx, .docm)
  • PDF/A (.pdf)


  • Comma-separated values (.csv)
  • SIARD (.siard)
  • SQL (.sql)
  • Tab-separated values (.csv)
  • dBase III eller 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)
  • Comma-separated values (.csv)
  • MS Excel (.xls, .xlsx)
  • R (.rdata, .rda)
  • SAS (.sas)
  • SAS transport (.xpt)

Raster images

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

Vector images

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


  • Lossless AVI (.avi)
  • Matroska (.mkv)
  • Motion Jpeg 2000 (.mj2, .mjp2)
  • 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)
  • Material eXchange Format (MXF) (.mxf)
  • 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)

  • Digital Elevation Model (DEM) Format (.dem)
  • Geographic Markup Language (.gml)
  • Keyhole Markup Language (.kml)
  • GeoTIFF (.tif, .tiff)
  • CSV (.csv)
  • GeoJSON (.geojson)
  • 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



  • COLLADA (.dae)
  • Comma-separated values (.csv)
  • 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)