Last updated April 12, 2014. Created by drunken monkey on May 20, 2013.
Edited by beltofte, Brian Altenhofel, junipllc, maciej.zgadzaj. Log in to edit this page.

This section lists modules that add new backends, plugins or other extensions to the Search API, allowing users to add additional functionality to their sites. Creators of new extension modules are welcome to add their projects to this list, too.

This page also acts as the parent for documentation on those extension modules.

Modules providing service classes

Solr search
A backend using an Apache Solr server for indexing and searching, like the popular Apache Solr Search Integration module. It uses dynamic fields for indexing arbitrary entities and boasts far superior indexing- and search-performance, better result accuracy and native facetting support.
Database search
A simple, database-based backend for indexing and searching data. It's neither very fast nor accurate, but it works out of the box and can be used for testing out the Search API capabilities (it even supports facetting), or for smaller sites (or smaller, less important indexes/searches).
Fuzzy Search
A more advanced database-based backend which also allows fuzzy matches and substring matching.
Xapian
The xapian project now includes a separate module, search_api_xapian, that provides a Xapian backend for the Search API. Facets currently aren't supported yet, but planned for the future (as of January 2011).
Sarnia
Sarnia is an extension of the Solr search module which provides the capability to search and display non-Drupal data indexed in Solr.
Mongo DB backend
Uses a Mongo DB for indexing and searching. Fast and scalable, it's a great alternative to the normal database backend.
Sphinx
Uses Sphinx for indexing and searching. Supports several features, including facets and "More Like This".
Elasticsearch
Uses Elasticsearch for indexing, analysis, and searching. Facets, autocomplete, and "more like this" are currently supported features with new features being added on a regular basis.
Elasticsearch Connector
Elasticsearch Connector is a set of modules designed to build a full Elasticsearch eco system in Drupal. It is using the official Elasticsearch PHP library. One of the biggest companies are using Elasticsearch for big data - check this out. The ambitions of this module is to help Drupal handle big data at any kind and make it scalable.

Other extension modules

Search pages
A module for creating simple search pages, not using Views or any other modules. They can be used when a view would be unnecessarily slow, or for quickly testing out functionality. They also provide search blocks for starting a search from anywhere on the site.
Multi-index searches
An extension for executing a search query on several indexes at once, for servers supporting that feature (like servers with the Solr backend).
Saved searches
Lets users create search notifications so they are notified when new results are available.
Autocomplete
Allows to add dynamic autocompletion to fulltext key fields on search forms.
Search API attachments
An extension that uses the Apache Tika library to allow indexing of attachment (or other file) contents.
Extended search page
This module provides a page like the default "Find content" page, but based on the Search API and therefore more flexible and richer in features.
Pretty Facets Paths
Allows site admins to rewrite the facet URLs for taxonomy terms to use the path instead of additional GET parameters.
Search API ranges
Adds the ability to add range facets for numeric fields to searches, with a nice ruler UI.
Search API sorts
Offers highly configurable sort blocks for all searches.
Search API context
Provides "context-sensitive" blocks for Search API.
Search API AJAX
Provides base functionality for AJAXifying search pages.
Search API Location
Allows indexing and searching of geolocation data with the Solr backend.
Search API live results
Alternative to Autocomplete that shows potential results while typing.
Search API Entity Translation
Search API Entity Translation allows you to index items in several languages when using Entity translation, as well as offering a few other tools for multilingual sites.
Search API Override
This module allows you to override Search API server settings from within settings.php – the prime use being to override servers stored in features on development and staging servers.

Looking for support? Visit the Drupal.org forums, or join #drupal-support in IRC.