Communication Services & Information Technology
University of California
Communication Services & Information Technology

Recommended Archive Formats


Type of data Preferred formats for management back-ups and data preservation Other acceptable formats for data preservation

Quantitative tabular data with extensive metadata

a dataset with variable labels, code labels, and defined missing values, in addition to the matrix of data

SPSS portable format (.por)

delimited text and command ('setup') file (SPSS, Stata, SAS, etc.) containing metadata information

structured text or mark-up file containing metadata information, e.g. DDI XML file

proprietary formats of statistical packages e.g. SPSS (.sav), Stata (.dta)
MS Access (.mdb/.accdb)

Quantitative tabular data with minimal metadata

a matrix of data with or without column headings or variable names, but no other metadata or labelling

comma-separated values (CSV) file (.csv)

tab-delimited file (.tab)

including delimited text of given character set with SQL data definition statements where appropriate


delimited text of given character set - only characters not present in the data should be used as delimiters (.txt)

widely-used formats, e.g. MS Excel (.xls/.xlsx), MS Access (.mdb/.accdb), dBase (.dbf) and OpenDocument Spreadsheet (.ods)

Geospatial data

vector and raster data

ESRI Shapefile (essential - .shp, .shx, .dbf, optional - .prj, .sbx, .sbn)

geo-referenced TIFF (.tif, .tfw)

CAD data (.dwg)

tabular GIS attribute data


ESRI Geodatabase format (.mdb)

MapInfo Interchange Format (.mif) for vector data

Keyhole Mark-up Language (KML) (.kml)

Adobe Illustrator (.ai), CAD data (.dxf or .svg)

binary formats of GIS and CAD packages

Qualitative data


eXtensible Mark-up Language (XML) text according to an appropriate Document Type Definition (DTD) or schema (.xml)

Rich Text Format (.rtf)

plain text data, ASCII (.txt)

Hypertext Mark-up Language (HTML) (.html)

widely-used proprietary formats, e.g. MS Word (.doc/.docx

proprietary/software-specific formats, e.g. NUD*IST, NVivo and ATLAS.ti


Digital image data TIFF version 6 uncompressed (.tif)

JPEG (.jpeg, .jpg)

TIFF (other versions) (.tif, .tiff)

Adobe Portable Document Format (PDF/A, PDF) (.pdf)

RAW image format (.raw)

software-specific formats, e.g. Photoshop files (.psd)

Digital audio data

Free Lossless Audio Codec (FLAC) (.flac)

Waveform Audio Format (WAV) (.wav)

MPEG-1 Audio Layer 3 (.mp3)

Audio Interchange File Format (AIFF) (.aif)

Digital video data

MPEG-4 (.mp4)

motion JPEG 2000 (.mj2)



Documentation and scripts Rich Text Format (.rtf)
PDF/A or PDF (.pdf)
HTML (.htm)
OpenDocument Text (.odt)

plain text (.txt)

widely-used proprietary formats, e.g. MS Word (.doc/.docx) or MS Excel (.xls/.xlsx)

XML marked-up text (.xml) according to an appropriate DTD or schema, e.g. XHMTL 1.0

Table from the UK Data Archive

Webmaster Email: