Apache Solr vs Relevanssi

Apache Solr is a free, open-source, self-hosted search platform built on Apache Lucene. It provides full-text, vector, geospatial, and hybrid search through a REST query interface. Documents can be sent over HTTP as JSON, XML, CSV, or binary, with results returned in those formats. Matching supports phrases, wildcards, joins, and grouping; discovery tools include faceting, autocomplete, spelling suggestions, hit highlighting, and result clustering. Solr distributes indexing, replicates data, balances queries, and supports automated failover and recovery. Apache Tika integration extracts rich content such as PDF and Microsoft Word files. Its administrative interface controls instances and exposes cluster state, logs, threads, and metrics. Listed security capabilities include SSL, authentication, and role-based authorization. Solr runs on Linux, macOS, and Windows, with API access, and is licensed under Apache License, Version 2.0. The project describes use from weekend projects to global enterprises. Releases are not scheduled in advance, and versions below 9.10 are end of life without further updates. The Apache Solr plan is free.

Relevanssi has no write-up on Specifiction yet; its figures are above.