Arolsen Archives – https://arolsen-archives.org/en/
The international center on Nazi persecution with the world’s most comprehensive archive on the victims and survivors of National Socialism. The collection has information on about 17.5 million people and belongs to UNESCO’s Memory of the World. It contains documents on the various victim groups targeted by the Nazi regime.

Czestochowa-Radomsko Area Research Group – https://www.crarg.org/polish-holocaust-database.php
Access their search engine that gives access to one of the largest collections of archival Holocaust data on the web.

U.S. Holocaust Memorial Museum Collections and Archives and Research Center (USHMM) – https://www.ushmm.org/
The USHMM collects evidence of the Holocaust that documents the fate of victims, survivors, rescuers, liberators, and others. The collection contains millions of documents, artifacts, photos, films, books, and testimonies. It is the items that belonged to those victims and survivors—as well as other materials that relate their stories, experiences, and histories—that form the basis of the Museum’s collections.

Yad Vashem – https://www.yadvashem.org/
As the Jewish people’s living memorial to the Holocaust, Yad Vashem aspires to list every one of the 6 million Shoah victims, safeguarding the memory of the past and imparting its meaning for future generations. Established in 1953, as the world center for documentation, research, education and commemoration of the Holocaust, Yad Vashem is today a dynamic and vital place of intergenerational and international encounter.