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Preferred File Formats

In order to support longevity and reuse of digital files, the Libraries prefers these file formats.

To maximize the ability to share, preserve and re-use digital files, you will want to carefully consider the format you use for digital files. Careful selection of a file format can also help you down the road by limiting the chances of your data becoming obsolete when a proprietary format is no longer supported.

In general, UW Libraries encourages you to use file formats that are Open format (or free file formats–well-documented), non-proprietary, commonly used within your field or discipline; that have a standard encoding (ASCII, Unicode); and are not otherwise encrypted or compressed.

Format Highest Confidence Medium Confidence Lowest Confidence

Plain text — US-ASCII, UTF-8, UTF-16 with BOM (.txt)

SGML with included DTD (.sgm, .sgml)

XML with included schema (.xml)

PDF/A-1 —  ISO 19005-1 (.pdf)

Plain text — ISO 8859-x (.txt)

Rich Text Format 1.x (.rtf)

Cascading Style Sheets (.css)

HTML (.html, .htm)

LaTeX with referenced files (.latex)

OpenDocument Text (.odt, .sxw)

MS Word 2007+ (OOXML) (.docx)

PDF with fonts embedded (.pdf)

Microsoft Word (.doc)

WordPerfect (.wpd)

all others

Digitized Books, Maps, Paper etc.

JPEG2000 — lossless (.jp2)

TIFF — uncompressed (.tiff)

PDF/A-1 —  ISO 19005-1 (.pdf)

n/a All others

Raster Graphics



TIFF — uncompressed or CCITT 4 compressed (.tiff)

JPEG2000 — lossless compression (.jp2)

PNG (.png)–24bit true color

TIFF — compressed (.tiff)

JPEG (.jpg)

JPEG2000 — lossy compression (.jp2)

GIF (.gif)

Digital Negative DNG (.dng)

BMP (.bmp)

PNG (.png)–8 bit indexed

PhotoShop (.psd)

MrSID (.sid)

RAW files

All others

Vector Graphics


SVG — no JavaScript binding (.svg)

PDF/A-1 —  ISO 19005-1 (.pdf)

Computer Graphics Metafile (.cgm)

Encapsulated Postscript (.eps)

Macromedia Flash (.swf)

all others

Digitized Audio

BWAV LPCM (.bwav, .wav)

24-bit, 96kHz

n/a All others.
Born Digital Audio

AIFF — PCM (aif, aiff) LPCM codec.

WAV — PCM (.wav)

LPCM codec

SUN audio — uncompressed (.au, .snd)

Standard MIDI (.mid)

Free Lossless Audio Codec (.flac)

Apple Lossless Audio Codec (ALAC) (.m4a)

MP3 (.mp3)

Advance Audio Coding (.mp4)

AIFC — compressed AIFF (.aifc)

RealAudio (.rm, .ra)

Windows Media Audio (.wma)

WAV — compressed (.wav)

Ogg Vorbis (.ogg) (LOSSY)

all others

Digitized Video

FFV1/Matroska (.mkv)

AVI — uncompressed (.avi)

QuickTime — uncompressed, motion JPEG (.mov)

Uncompressed .mxf

Motion JPEG 2000 (.jp2) ProRes  (.mov)
Born Digital Video

FFV1/Matroska (.mkv)

AVI — uncompressed (.avi)

QuickTime — uncompressed, motion JPEG (.mov)

Uncompressed .mxf

MPEG-4 (.mp4) H.264

MPEG-1, MPEG-2 (.mp1, .mp2)

Ogg Theora (.ogv, .ogg)

ProRes  (.mov)

Motion JPEG 2000 (.jp2)

Windows Media Video (.wmv)

RealVideo (.rm, .rv)

all others

Spreadsheet or Database


Comma- or tab-separated Values (.csv, .tsv, .txt)

Delimited text

SIARD: Software Independent Archiving of Relational Databases (.siard)

dBASE (.dbf)

OpenDocument Spreadsheet (.ods)

MS Excel 2007+ (OOXML) (.xlsx)

Excel (.xls)

all others

Computer Programs Computer program source code Compiled / Executable files
Presentation PDF/A-1 —  ISO 19005-1 (.pdf)

OpenDocument Presentation (.odp)

MS Powerpoint 2007+ (OOXML) (.pptx)

PowerPoint (.ppt)

all others


GeoTIFF (.tif)

GeoJSON (.json, .geojson)

ESRI Shapefile (making sure all component files are present) (.shp, .shx, .dbf)

ESRI Geodatabase (.gdb) (prefer Shapefiles)

ESRI Export Format (.e00)

Geography Markup Language (GML) (.gml)

Keyhole Markup Language (KML) (.kml, .kmz)

Other ESRI files

Zip –no compression


Zip- compressed All others

Quantitative and Statistical Data


(See also: Spreadsheet or Database)

Comma- or tab-separated Values (.csv, .tsv, .txt)

Structured text or markup file containing metadata information:

Data Documentation Initiative (.ddi), XML (.xml), JSON (.json)

SIARD: Software Independent Archiving of Relational Databases (.siard)

HDF5 (.hdf)

SPSS (.sav, .sps, .spv, .spo)

SAS (.sas, .sas7dat)

R (.R)

HDF4 (.hdf)

Excel (.xls)

Other proprietary formats



(See also: Vector Graphics)

Industry Foundation Class (.ifc)

Standard for the Exchange of Product Model Data (.step, .stp, .p21)

Initial Graphics Exchange Specification (.igs)

AutoDesk’s Drawing Interchange File Format/Data eXchange Format (.dxf)

AutoCAD (.dwg)

Extensible 3D (.x3D)

Universal 3D (.u3D)

Portable Document Format/Engineering or PDF3D (.pdf)

Other proprietary CAD formats





All others