Apache Lucene Core

Apache LuceneTM is a high-performance, full-featured text search engine library written entirely in Java. It is a technology suitable for nearly any application that requires full-text search, especially cross-platform.

Apache Lucene is an open source project available for free download. Please use the links on the right to access Lucene.

Lucene TM Features

Lucene offers powerful features through a simple API:

Scalable, High-Performance Indexing

over 150GB/hour on modern hardware

small RAM requirements -- only 1MB heap

incremental indexing as fast as batch indexing

index size roughly 20-30% the size of text indexed

Powerful, Accurate and Efficient Search Algorithms

ranked searching -- best results returned first

many powerful query types: phrase queries, wildcard queries, proximity queries, range queries and more

fielded searching (e.g. title, author, contents)

sorting by any field

multiple-index searching with merged results

allows simultaneous update and searching

flexible faceting, highlighting, joins and result grouping

fast, memory-efficient and typo-tolerant suggesters

pluggable ranking models, including the Vector Space Model and Okapi BM25

configurable storage engine (codecs)

Cross-Platform Solution