WieWasWie is a Dutch genealogy and family-history research platform that helps people discover their ancestors through historical records. Its searchable database covers more than 252 million people and draws on over 230 million historical and genealogical sources. Visitors can search for names, explore old documents, and view original records, with tools for more detailed searches. The collection is contributed by participating archives and heritage institutions across the Netherlands, including the National Archives, regional archives, and CBG|Centre for Family History.

For researchers who want additional search options, WieWasWie offers Premium access. Subscribers can search for two people at once and use wildcards to find names with different spellings. The site also explains how to investigate recently deceased relatives who may not appear in its records because of privacy rules, and provides information about requesting an extract from the National Register of the Deceased. Alongside its research services, WieWasWie publishes family-history news and offers guidance to help users explore their roots.