What Is a GEDCOM File? A Beginner's Guide to the .ged Format

GEDCOM is the universal file format for family trees. Learn what a .ged file contains, who created it, and how to use it to move your tree between programs.

If you have ever exported a family tree from Ancestry, MyHeritage or FamilySearch, you have met a GEDCOM file. It is the one format that almost every genealogy program can read and write, and it is the file PrintFamilyTree turns into charts and books. Here is what is inside it and why it matters.

The short definition

GEDCOM stands for GEnealogical Data COMmunication. It is a plain-text file with the extension .ged that describes people, the families they belong to, the events of their lives and the sources you used to prove them. The format was created by The Church of Jesus Christ of Latter-day Saints in 1984 so that researchers could exchange data between programs that otherwise had nothing in common.

What a .ged file looks like

Open a GEDCOM file in a text editor and you will see numbered lines like these:

• 0 @I12@ INDI starts an individual record with the identifier I12.
• 1 NAME Anna /Kowalska/ gives the name; the surname is between slashes.
• 1 BIRT followed by 2 DATE 12 MAR 1901 and 2 PLAC Kraków, Poland records a birth.
• 1 FAMS @F4@ links the person to a family in which she is a spouse.
• 0 @F4@ FAM starts a family record with HUSB, WIFE and CHIL lines.

The number at the start of each line is the level: level 1 lines belong to the level 0 record above them, level 2 lines belong to the level 1 line above them, and so on. That is the whole trick. Once you can read levels, you can read any GEDCOM file.

Versions you will encounter

• GEDCOM 5.5 and 5.5.1 are the versions most programs export today. 5.5.1 added UTF-8 encoding, which matters a lot if your ancestors had names with accents or Polish, Czech or German letters.
• GEDCOM 7.0 was published in 2021. It cleans up many ambiguities and allows attached media in a ZIP package, but adoption is still gradual.
• Vendor extensions are lines starting with an underscore, such as _MREL for the relationship of a mother to a child in Family Tree Maker. Good tools keep what they understand and ignore the rest without breaking.

Why you should keep a GEDCOM copy of your tree

Your online tree is only as safe as the company hosting it. A GEDCOM export is the one copy of your work that belongs entirely to you. Export it after every big research session, keep it with your backups, and you will never lose years of work to a closed account or a discontinued product.

A GEDCOM file is also the fastest way to get a printed result. Upload it to PrintFamilyTree and every person, marriage and date becomes a box on a diagram or a paragraph in a book, without retyping anything.

Common problems and easy fixes

• Strange characters in names: the file was saved in an old encoding. Re-export with UTF-8 if your program offers the option.
• Missing people: some programs export only a branch or hide living people. Check the export settings.
• Duplicate individuals: merging trees often leaves two records for one person. Most desktop programs have a find duplicates tool.

Once you know the format, the .ged file stops being a mystery and becomes the most portable, durable record of your family history you own.