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OpenSearch is a collection of technologies that allow publishing of search results in a format suitable for syndication and aggregation. It is a way for websites and search engines to publish search results in a standard and accessible format.

Example of a web page which offers to add a new search plugin. With Firefox, the symbol of the currently selected search engine becomes bluish. The user can add the search engine offered by that page by clicking the triangle.
Initial releaseMarch 15, 2005 (2005-03-15)
Latest release
1.1[citation needed]
(December 6, 2005; 13 years ago (2005-12-06))
Type of formatWeb syndication
Extended fromRSS
Open format?Creative Commons Attribution-ShareAlike 2.5

OpenSearch was developed by subsidiary A9 and the first version, OpenSearch 1.0, was unveiled by Jeff Bezos at the O'Reilly Emerging Technology Conference in March, 2005. Draft versions of OpenSearch 1.1 were released during September and December 2005. The OpenSearch specification is licensed by A9 under the Creative Commons Attribution-ShareAlike 2.5 License.[1]


Web browsers that support OpenSearch include Safari,[2] Microsoft Edge,[3] Firefox[4] and Google Chrome.[5]


Search suggestions in the German Wikipedia

OpenSearch consists of:

  1. OpenSearch Description files: XML files that identify and describe a search engine.
  2. OpenSearch Query Syntax: describe where to retrieve the search results
  3. OpenSearch RSS (in OpenSearch 1.0) or OpenSearch Response (in OpenSearch 1.1): format for providing open search results.
  4. OpenSearch Aggregators: Sites that can display OpenSearch results.
  5. OpenSearch "Auto-discovery" to signal the presence of a search plugin link to the user and the link embedded in the header of HTML pages

OpenSearch Description Documents list search result responses for the given website/tool. Version 1.0 of the specification only allowed one response, in RSS format; however, version 1.1 provides support for multiple responses, which may be in any format. RSS and Atom are the only ones formally supported by OpenSearch aggregators, however other types, such as HTML are perfectly acceptable.

  • Auto-discovery of an OpenSearch Description Document is available from both HTML and Atom or RSS feed documents via Link relations in the form of <atom:link rel="search" ... /> for Atom feeds[6] or <link rel="search" ... /> for RSS feeds[6] and HTML documents.[7]
  • OpenSearch Description Document must be placed on a web server of the same domain.[8]
  • OpenSearch Description Documents must be served with the application/opensearchdescription+xml Internet media type.[9]

See alsoEdit


  1. ^ "OpenSearch / Specifications / License". August 24, 2015.
  2. ^ "What's New in Safari 8.0". Apple Developer. Apple. 2014-10-16. Retrieved 2017-03-27.
  3. ^ "See and select OpenSearch engine for Microsoft Edge". Retrieved 2017-07-23.
  4. ^ Ponomarev, Nickolay (9 Sep 2007). "Supporting search suggestions in search plugins". Mozilla Developer Center. Mozilla. Retrieved 2007-08-03.
  5. ^ Google Chrome FAQ for web developers (on Internet Archive) "By providing an OpenSearch description document (OSDD), you enable Google Chrome to include your site in the list of search engines in the browser."
  6. ^ a b "Specifications/OpenSearch/1.1/Draft 5 – OpenSearch".
  7. ^ "Specifications/OpenSearch/1.1/Draft 5 – OpenSearch".
  8. ^ "Developer how to guide". Open Search. Retrieved 8 August 2018.
  9. ^ "Specifications/OpenSearch/1.1/Draft 5 – OpenSearch".

External linksEdit

  • Official website, including specifications
  • Mycroft Project [1] collection of OpenSearch installers for Firefox