People have been creating mechanized family trees for decades using genealogy software. This permitted production of data extract files, and printed reports, to share with others. The GEDCOM is the genealogy industry’s common standard file format that allows the export, exchange, and import of genealogical data from one software package to another. It is also used to produce a file that can be extracted from your software and uploaded to online database services to create an online family tree. The resultant tree is presented to a user to be viewed in structured formats that genealogists recognize pedigree chart, family group, and individual personal details. A GEDCOM will also transfer source citations and notes if desired. It will not transfer images, audio and video files, and other connected media.

There are numerous online sites that accept, store, and allow searching of online family trees. The most prolific of these in terms of size and numbers of family trees online are Ancestry.com, FamilySearch.org, Findmypast.com, JewishGen.org, MyHeritage.com, and Fold3.com. Other active sites include Geni.com, FamilyHistory.uk.com and GenesReunited.com in the UK. Individuals also create their own stand-alone websites with family trees.