An index to more than 10 million New York City birth, marriage and death records from 1866 to 1948 is available free online thanks to a collaboration between the city’s Department of Records and Ancestry.com.

While access to the index is free, the documents themselves must be purchased from the city.

“When researching the American side of your family history, the likelihood of an ancestor either living in New York City or immigrating through it is very high,” said Todd Godfrey, director of content acquisition at Ancestry.com.

“We are pleased to have teamed up with Ancestry.com in making this easily searchable index of New York City’s vital records available online for free,” said Eileen Flannelly, commissioner of the city’s Records Department. The indexes were created by volunteers from the Italian Genealogical Group and the German Genealogy Group, Ms. Flannelly said.

The index can be found here. (This is a different, better link than the one originally published here.)