What is a GEDCOM file?
The GEDCOM file format was created by The Church of Jesus Christ of Latter-day Saints (aka the Mormon church) as a means of transferring family tree data from one genealogical website or software to another. GEDCOM is an acronym for Genealogical Data Communication and the original GEDCOM file specification was released in 1984 with the latest version, GEDCOM 7.0 released in 2021.
All major family history software products and websites support the GEDCOM file format. This means that if you have your family tree stored on a website or you have created it using standard family tree building software, then you should be able to export your tree easily to upload it elsewhere.
GEDCOM files use the ‘.ged’ suffix (just as a Word document, for example, has the suffix ‘.doc’). If someone shares a .ged file with you, then you will need to upload it to a family tree website or software to be able to read it.
How does GEDCOM work?
The GEDCOM specification is just an agreed format for building a database, which is essentially what a family tree is. For example, it will have a field for someone’s first name and another field for someone’s surname that will be recognised by all family tree programmes that support GEDCOM files. It also recognises family structures and groups people and sources together.
If you want a more technical account of how the software works, there is a helpful description on Wikipedia.
There are limitations with GEDCOM and over the years new versions have tried to iron out some of these problems including limited ideas of what constitutes a family unit, for example same-sex marriages. The format is also used slightly differently by different products which can cause problems when exporting and importing. Some products may not import some of the more free form notes fields, for example.
This means it is important to be aware that not everything you may have added to your family tree will import into a new programme from a GEDCOM file.
What is GEDCOM 7.0?
One of the main limitations of previous versions of GEDCOM was that old photographs and other images added to a family tree could not easily be transferred over. GEDCOM 7.0 has changed that by adding zip packaging capabilities known as GEDZip so that large amounts of data can be transferred over and unzipped in a way that maintains the connection between the images and the individual they are attached to.
Notes have also been expanded making them more versatile and enabling easier transfer from one package to another and sources can include internet links as well as local files.
As GEDCOM 7.0 has only just been released, companies that support previous versions may not yet support the latest version. You can read about the latest developments on their website.