As the memory of the city of Mainz, the city archive secures and indexes all important documents on the history of Mainz. From medieval parchment documents to digital data carriers, the archive preserves the entire range of historical sources. Official documents from the Mainz city administration and its predecessors were no longer needed there and were handed over to the archive. In addition, the City Archive collects the estates of important Mainz personalities as well as of companies, clubs, associations and political parties. The important collections of the City Archive also include the coin cabinet, a collection of seals and a collection of pictures and plans with about 150,000 photos and 20,000 plans.
Having arrived in the digital age for more than a decade, more than 80,000 title records are now available for research on the City Archive's website. The Stadtarchiv Mainz was also represented in the BAM portal as one of only a few municipal archives. There is therefore no question that the Stadtarchiv was also present at the launch of the archive portal D.