BASE is one of the world’s most voluminous search engines especially for academic web resources. The index contains more than 400 million records from more than 12,000 content providers. You can access the full texts of about 60% of the indexed records for free (Open Access). BASE is operated by Bielefeld University Library.

We are indexing the metadata of all kinds of academically relevant resources – journals, institutional repositories, digital collections etc. – which provide an OAI interface and use OAI-PMH for providing their contents (see our Golden Rules for Repository Managers).

The index is continuously enhanced by integrating further sources / content provider (Become a content provider). We are working on several new features like a claiming service for authors within the ORCID DE project.

BASE is a registered OAI service provider. Database managers can integrate the BASE index into their local infrastructure (for examplee.g. meta search engines, library catalogues). Further on there are several tools and services for users, database and repository managers.

In comparison to commercial search engines, BASE is charcterised by the following features:

• Content providers are indexed only after check by qualified personnel of Bielefeld University Library
• Only document servers and journals that comply with the specific requirements of academic quality and relevance are included
• Our list of content providers provides transparency in the searches
• Discloses web resources of the “Deep Web”, which are ignored by commercial search engines or get lost in the vast quantity of hits
• Correction, normalization and enrichment of metadata by means of automated methods
• Mulitlingual search (find search terms in more than 20 translated languages)
• The display of search results includes precise bibliographic data
• Display of access and terms of re-use for a document
• Several options for sorting the result list (by author, title, date)
• “Refine your search result” options (by author, subject, DDC, year of publication, content provider, language, document type, access and terms of re-use)
• Browsing by DDC (Dewey Decimal Classification), document type, access and terms of re-use / licence.