Open-Source Search Engine

YaCy is a scalable web search engine with an integrated web crawler and content analysis and managements functions. One YaCy installation can store more than 20 million documents, but in a community of search peers YaCy can provide a search index of unlimited size.

Peer-to-Peer Index Sharing

We implemented a index sharing method, that works similar to peer-to-peer file sharing. YaCy shares web index information with other peers and is therefore resistant against censoring the same way as P2P file-sharing is resistant against deletion.


View and download the demo movie in HD

Decentralized Architecture

This is the public network that you can join to use and support a large-scale free and uncensored search:

Your own search portal!

If you run a YaCy peer, you have your own search engine. You can use it either to provide search functionality for your own search portal, or you can join a community of search engine peers to share your web index with the web index of other YaCy peer owners. If you search with YaCy your search request are anonymous because they go to your computer and not to a central search portal server. No central server can log your searches.

Security for You

  • Your private search requests should never be stored, monitored, evaluated and be applied for commercial aspects. If you think this is important, then you should not use a search portal. YaCy is a secure alternative to search portals.
  • If you search for the purpose of product development and innovation, you give away information about your secret company knowledge by putting in words about such details in a search form that points to a central search service. To maintain your business secrets, you need your own search engine which can easily be created with YaCy.

Its easy!

Installation of YaCy takes only three minutes! Just download, decompress, start. Everything you need is included, no set-up of web servers, databases or anything else. No command-line interface, all administration tasks are done in a web front-end that is included in YaCy.