Sphinx is a standalone full-text search engine whose goal is to provide fast and relevant full-text search functionality. It is built to integrate with SQL databases, and to provide easy access via scripting languages, but it can be used directly without an SQL database.[05]

The Sphinx search daemon can be accessed via:
- SphinxQL, Sphinx's implementation of the MySQL network protocol that uses a subset of SQL.
- SphinxAPI, Sphinx's native search API, provided in PHP, Perl, Python, Ruby, and Java.
- Through MySQL server using SphinxSE, a storage engine component.

Sphinx provides two indexing backends:
- Disk: supports online full-text index rebuilds, but online updates can only be done to attribute data.
- Realtime: also allow online full-text updates.

Sphinx can use the following types of data sources to load disk indexes:
- MySQL .
- PostgreSQL .
- MSSQL .
- ODBC databases .
- TSV/XML files . + Can also work with custom source drivers.

The name of Sphinx refers to SQL Phrase Index.