In the integrated OPAC the complete holdings and collections of the library (History and Music History) are avaiable. This online catalogue replaces the two old separate OPAC, which were discontinued on January 1st, 2021.

The library pertains to the Südwestdeutscher Bibliotheksverbund library system (SWB) and the catalogue K10plus-Verbundkatalog will gradually include its complete collection. Journals held by the DHI will be inserted in the Zeitschriftendatenbank (ZDB – Journal Data Base) and in the Elektronische Zeitschriftenbibliothek (EZB – Electronic Journal Library).

In Rome the DHI is part of the Urbis Library Network, which brings together various international institutions, and its metacatalogue.