The Indexed Database API, or Indexed DB (formerly WebSimpleDB), is a proposed[1] web browser standard interface for a local database of records holding simple values and hierarchical objects. Indexed DB was initially proposed by Oracle in 2009.[2]
Indexed DB could be used for browser implemented functions, such as bookmarks, as well as web applications, such as email. An open-source reference implementation of the Indexed Database API exists for testing and experimentation purposes.[3]
Indexed DB is partially implemented in the Firefox 4 beta[4] and Google Chrome 11 canary.
Safari, Chrome 4 and Opera support[5] an alternate mechanism for client-side database storage called Web SQL Database [6]. On November 18, 2010, the W3C announced that Web SQL database is a deprecated specification[7]. Firefox developers have publicly stated that the lack of WebSQL Database support in Firefox is on purpose, as they believe it is a problematic standard which requires an alternative (hence IndexedDB)[8].