SALT LAKE CITY — FamilySearch.org launched a new function Tuesday that allows users to build same-sex family trees on its free website, completing a project previously announced by one of the world’s largest collections of genealogical data.

The popular website’s Family Tree feature now allows users to add a spouse or parent of the same sex.

“We’re adding functions that allow people to document family relationships as they exist,” said Paul Nauta, FamilySearch’s public affairs manager.

FamilySearch CEO Steve Rockwood announced the new function at the organization’s annual RootsTech event in 2017, Nauta said.

“The goal of FamilySearch is to enable individuals to discover themselves and their families,” Nauta added. “We do that by continuing to add new services and functions that enable individuals and families to create ongoing connections and discoveries in a very fun way.”

The new function allows FamilySearch to capture accurate genealogy “that represents past, present and future families of the world.”

The new function required a significant redesign to systems surrounding Family Tree. Nauta said a beta version of the function was provided six months ago to designers of third-party apps that use FamilySearch Family Tree so they could prepare for today’s launch.

Family Tree is the world’s largest collection of free family trees and is accessible to anyone. The feature allows FamilySearch’s 13.9 million users to collaborate on a single, shared, freely accessible worldwide family tree. Users have placed more than 1.2 billion people in the tree.

Users of the Family Tree mobile app will need to install an update to use the new function.

FamilySearch is a nonprofit, volunteer-driven organization sponsored by The Church of Jesus Christ of Latter-day Saints. FamilySearch’s vast database includes 4.85 billion searchable records and 7.24 billion searchable names.

The church continues to teach that marriage between a man and a woman is a central part of its doctrine and practice. Sealings, which occur in the church’s temples, yoke the couple together not just for this life, but into the next life as well, according to church doctrine. Today’s announcement makes no change to church doctrine on marriage, according to a church statement and Q&A released by the church.

“All of Heavenly Father’s children throughout the world will be able to document their family relationships as they exist, particularly based on source documents that exist,” Nauta said. “We’re happy to be able to successfully launch that today.”

FamilySearch announced in April 2018 that it expected to complete the project redesign by the end of 2019.

Thomas MacEntee, a Chicago-based genealogist who speaks annually at FamilySearch’s RootsTech expo and is married to another man, welcomed the new function.

“We’ve been waiting for this for years,” he said.

MacEntee is the CEO and founder of abundantgenealogy.com, which offers free instruction on genealogy as well as LGBT genealogy resources. He said FamilySearch was the last major online family tree program without same-sex capability.

“Right now I have my husband, George, in the tree, but I’m forced to have him displayed as a female,” MacEntee said.

His spouse is from Greece and he has wanted to use FamilySearch’s robust tools for gathering family photos and history in one place.

“Now I can take advantage of things on FamilySearch like photos and family stories,” he said. “I feel my family is much more complete today than it was yesterday, at least from the way it shows up on FamilySearch.”