Fess

Fess is an enterprise full-text search server designed to index and search content from multiple sources such as websites, file systems, and data stores. It provides a browser-based administration UI and can run anywhere a Java runtime (or Docker) is available.

Key Features

• Web-based admin console to configure crawlers, indexing, and search UI settings
• Built-in crawler for web content, file systems, and network shares, with support for many document formats (for example PDF and Microsoft Office)
• Search backed by OpenSearch (and can also utilize Elasticsearch)
• Faceted search, drill-down, and result labeling to improve discovery
• Search and click log collection for analysis and relevance tuning
• Extensible architecture with plugins and integrations, including JSON-based API output
• Secure crawling and search options, including authenticated content and SSO integrations

Use Cases

• Internal enterprise search across intranet sites, shared folders, and document repositories
• Site search for public or private websites with embeddable JavaScript integration
• Unified search portal across multiple business systems via connectors and plugins

Fess is a practical choice when you need a deployable, configurable search server with crawling, administration, and extensibility packaged into a single solution. It fits well for organizations that want full control over indexing pipelines and search behavior while relying on OpenSearch-compatible search capabilities.