What is Open Semantic Search used for?

Open Semantic Search is a free, GPL-licensed research platform for searching and analyzing large document collections, combining semantic search with text mining and OCR. It is a good fit for investigative journalism document research, and exploring and analyzing large document archives.

Is Open Semantic Search open source?

Yes. Open Semantic Search is open source under the GPL-3.0 licence. Its source code is on GitHub at opensemanticsearch/open-semantic-search and is written mainly in Shell.

Is Open Semantic Search free?

Yes. Open Semantic Search is open source, so the software itself is free to use.

Can I self-host Open Semantic Search?

Yes. Open Semantic Search can be self-hosted on your own server or infrastructure; there is no official hosted version.

What is Open Semantic Search an alternative to?

Open Semantic Search is an open-source alternative to Coveo, Sinequa, Mindbreeze and Amazon Kendra. Other open-source alternatives to Coveo include Fess, Swirl and OpenSearchServer.

Is Open Semantic Search actively maintained?

The most recent commit to Open Semantic Search was on 19 April 2025. The project has 1.2k stars on GitHub.

Open Semantic Search: open-source alternative to Coveo

About Open Semantic Search

Open Semantic Search is a research tool aimed at journalists, researchers and analysts who need to search, browse, analyze and explore large collections of documents, going well beyond simple keyword search. It combines a semantic search engine with a full text mining and text analytics platform.

It includes an ETL framework for processing documents, covering crawling, text extraction, text analysis, named entity recognition for persons, organizations and locations, and OCR for images and embedded images inside PDFs. On top of that data pipeline, it provides metadata management through thesauri and ontologies using the SKOS standard, and search user interfaces and applications supporting full-text search, faceted search, exploratory search and knowledge graph search. Its topics specifically mention OSINT and investigative journalism as use cases.

Open Semantic Search can be built as a Debian or Ubuntu package, as a desktop search appliance for VirtualBox, or as a set of Docker images using the project's docker-compose configuration, which starts all the needed services together. It is written in Shell and Python, documented with MkDocs, and released under the GPL-3.0 license.

Key features

Semantic and faceted document search
Named entity recognition and OCR extraction
Thesaurus and ontology-based metadata management
Full ETL pipeline for document processing
Knowledge graph search
Docker, Debian and desktop VM deployment options

Good fit for

→Investigative journalism document research
→Exploring and analyzing large document archives

Built with: Shell; Python
Tags: semantic-search; text-mining; ocr; research-tool; self-hosted; osint; investigative-journalism

Open Semantic Search: questions and answers

What is Open Semantic Search used for?: Open Semantic Search is a free, GPL-licensed research platform for searching and analyzing large document collections, combining semantic search with text mining and OCR. It is a good fit for investigative journalism document research, and exploring and analyzing large document archives.
Is Open Semantic Search open source?: Yes. Open Semantic Search is open source under the GPL-3.0 licence. Its source code is on GitHub at opensemanticsearch/open-semantic-search and is written mainly in Shell.
Is Open Semantic Search free?: Yes. Open Semantic Search is open source, so the software itself is free to use.
Can I self-host Open Semantic Search?: Yes. Open Semantic Search can be self-hosted on your own server or infrastructure; there is no official hosted version.
What is Open Semantic Search an alternative to?: Open Semantic Search is an open-source alternative to Coveo, Sinequa, Mindbreeze and Amazon Kendra. Other open-source alternatives to Coveo include Fess, Swirl and OpenSearchServer.
Is Open Semantic Search actively maintained?: The most recent commit to Open Semantic Search was on 19 April 2025. The project has 1.2k stars on GitHub.