ChatNoir is the web search engine developed and maintained by the Webis group. Unlike traditional search engines such as Google or DuckDuckGo, ChatNoir does not index the live web but fixed snapshots of it while being transparent about any of its retrieval decisions. Thus, the main focus of ChatNoir is enabling retrieval research by providing the research community with easy and ready-to-use access to billions of indexed web pages and allowing for reproducible experiments on them. This relieves researchers of the burden of and all the issues coming with massive tera- and petabyte scale out, so they can focus on their actual tasks instead.

Currently, ChatNoir indexes the ClueWeb09 and ClueWeb12 web page collections and a periodically updated set of Common Crawl snapshots.

ChatNoir is available at