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(Redirected from Google Refine)
Developer(s)Freebase, then Google, now open source community
Initial releaseNovember 10, 2010; 13 years ago (2010-11-10)
Stable release
3.8.1[1] Edit this on Wikidata / 21 May 2024; 33 days ago (21 May 2024)
Written inJava[2]
PlatformMicrosoft Windows, Linux, macOS
Available inEnglish, Italian, Chinese, Japanese, French, German
LicenseBSD License
Websiteopenrefine.org Edit this on Wikidata

OpenRefine is an open-source desktop application for data cleanup and transformation to other formats, an activity commonly known as data wrangling.[3] It is similar to spreadsheet applications, and can handle spreadsheet file formats such as CSV, but it behaves more like a database.

It operates on rows of data which have cells under columns, similar to the manner in which relational database tables operate. OpenRefine projects consist of one table, whose rows can be filtered using facets that define criteria (for example, showing rows where a given column is not empty).

Unlike spreadsheets, most operations in OpenRefine are done on all visible rows, for example, the transformation of all cells in all rows under one column,[4] or the creation of a new column based on existing data. Actions performed on a dataset are stored the project and can be 'replayed' on other datasets. Formulas are not stored in cells, but are used to transform the data. Transformation is done only once.[5] Formula expressions can be written in General Refine Expression Language (GREL),[6] in Jython (i.e., Python), and in Clojure.[7]

The program operates as a local web app: it starts a web server and opens the default browser to


  • Cleaning messy data: for example if working with a text file with some semi-structured data, it can be edited using transformations, facets and clustering to make the data cleanly structured.[8]
  • Transformation of data: converting values to other formats, normalizing and denormalizing.
  • Parsing data from web sites: OpenRefine has a URL fetch feature and jsoup HTML parser and DOM engine.[9]
  • Adding data to dataset by fetching it from web services (i.e. returning JSON).[10] For example, can be used for geocoding addresses to geographic coordinates.[11]
  • Aligning to Wikidata (formerly Freebase[12]): this involves reconciliation — mapping string values in cells to entities in Wikidata.[13]

Supported formats[edit]

Import is supported from following formats:[14]

If input data is in a non-standard text format, it can be imported as whole lines, without splitting into columns, and then columns extracted later with OpenRefine's tools. Archived and compressed files are supported (.zip, .tar.gz, .tgz, .tar.bz2, .gz, or .bz2) and Refine can download input files from a URL. To use web pages as input, it is possible to import a list of URLs and then invoke a URL fetch function.

Export is supported in following formats:[16]

Whole OpenRefine projects in native format can be exported as a .tar.gz archive.


OpenRefine started life as Freebase Gridworks, developed by Metaweb and has been available as open source since January 2010.[17] On 16 July 2010, Google acquired Metaweb,[18] the creators of Freebase, and on 10 November 2010 renamed Freebase Gridwords Google Refine, releasing version 2.0.[19] On 2 October 2012, original author David Huynh announced that Google would soon stop its active support of Google Refine.[20][21][22] Since then, the codebase has been in transition to an open source project named OpenRefine.[23]


  1. ^ "Release 3.8.1". GitHub. 21 May 2024. Retrieved 22 May 2024.
  2. ^ "OpenRefine/OpenRefine - GitHub". GitHub. Retrieved 25 June 2017.
  3. ^ "openrefine.github.com". openrefine.org.
  4. ^ "Editing by transforming: Cell Editing wiki page from Refine documentation". Retrieved 18 April 2012.
  5. ^ "Comparison with spreadsheet software: Cell Editing wiki page in Refine documentation". Retrieved 18 April 2012.
  6. ^ General Refine expression language OpenRefine/OpenRefine Wiki GitHub. Github.com (2013-04-03). Retrieved on 2013-08-16.
  7. ^ "Expressions: Refine documentation". Retrieved 18 April 2012.
  8. ^ "Screencast: Google Refine 2.0 - Introduction (1 of 3) - editing government data". YouTube. Retrieved 18 April 2012.
  9. ^ "Stripping HTML: Refine documentation wiki page". Retrieved 18 April 2012.
  10. ^ "FetchingURLsFromWebServices wiki page: Refine documentation". Retrieved 18 April 2012.
  11. ^ "Screencast: Google Refine 2.0 - Data Augmentation (3 of 3) - using Openstreetmap Nominatim for geocoding and Freebase for augmentation". YouTube. Retrieved 18 April 2012.
  12. ^ "Schema Alignment: Refine documentation wiki page". Retrieved 18 April 2012.
  13. ^ "OpenRefine documentation: Reconciliation". GitHub. Retrieved 12 March 2017.
  14. ^ "Importers: Refine documentation wiki page". Retrieved 18 April 2012.
  15. ^ "Changelog for 2.5". Retrieved 18 April 2012.
  16. ^ "Exporting: Refine documentation wiki page". Retrieved 18 April 2012.
  17. ^ "Google Code Archive - Long-term storage for Google Code Project Hosting". code.google.com.
  18. ^ "Google Official Blog: Deeper understanding with Metaweb". Retrieved 18 April 2012.
  19. ^ "Google Opensource blog: Announcing Google Refine 2.0, a power tool for data wranglers". Retrieved 18 April 2012.
  20. ^ "Google Groups". groups.google.com.
  21. ^ "From Freebase Gridworks to Google Refine and now OpenRefine".
  22. ^ OpenRefine Archived 2016-09-25 at the Wayback Machine. OpenRefine. Retrieved on 2013-08-16.
  23. ^ google-refine - Google Refine, a power tool for working with messy data (formerly Freebase Gridworks) - Google Project Hosting. Code.google.com. Retrieved on 2013-08-16.

External links[edit]