GEDCOM vs GEDCOM-X: What's the Difference and Which Should You Use?

If you are exporting a family tree to share, save or analyse in 2026, export GEDCOM 5.5.1 or GEDCOM 7 - both are universally supported and round-trip cleanly between every major program. GEDCOM-X is a more modern format developed by FamilySearch, but it is still thinly supported by desktop genealogy software, so it is rarely the best choice for sending a tree to someone else.

That is about the wider ecosystem, not about us: GEDminer reads GEDCOM X in both of its forms, JSON and XML, so if a GEDCOM X file is what you have, upload it. The rest of this guide explains the difference between the two formats and where each one earns its place.

GEDCOM (GEnealogical Data COMmunication) is a plain-text format originally developed by The Church of Jesus Christ of Latter-day Saints in 1984 to let different genealogy programs exchange data. It is line-based, human-readable in a text editor, and uses simple level-numbered tags:

`

0 @I1@ INDI

1 NAME John /Smith/

1 BIRT

2 DATE 12 MAR 1850

2 PLAC London, England

`

Three versions are in current circulation: 5.5 (1995), 5.5.1 (2019, the de facto industry standard for two decades) and GEDCOM 7 (2021, the modern revision with cleaner UTF-8 handling, improved sourcing and richer media support).

GEDCOM-X is a separate format developed by FamilySearch, designed from scratch around modern web standards. It uses JSON or XML as its serialisation format, with a richer data model that makes it easier to represent sources, evidence, and analytical conclusions as first-class objects.

GEDCOM-X is not a new version of GEDCOM. It is a parallel, incompatible standard. A program that can read GEDCOM cannot necessarily read GEDCOM-X, and vice versa.

Format

• •GEDCOM: line-based plain text with level numbers and tags.
• •GEDCOM-X: structured JSON or XML.

Data model

• •GEDCOM: facts attached to individuals; sources optionally cited.
• •GEDCOM-X: evidence, conclusions and personas as first-class objects, more aligned with the Genealogical Proof Standard.

Adoption

• •GEDCOM: supported by every major desktop and online genealogy program for 30+ years.
• •GEDCOM-X: supported primarily by FamilySearch APIs; very limited desktop support in 2026.

File size

• •GEDCOM: compact (a few MB for tens of thousands of individuals).
• •GEDCOM-X: typically 2-3x larger as JSON, more if XML.

Tooling

• •GEDCOM: huge ecosystem of validators, viewers, converters.
• •GEDCOM-X: small ecosystem, mostly FamilySearch-internal.

For sharing with other people, backing up, or opening in third-party tools, export GEDCOM 5.5.1. Universal compatibility, mature tooling, and small file size.

If your software offers it and your destination supports it, GEDCOM 7 is a solid choice - it cleans up the encoding issues and modernises the spec without breaking compatibility too badly.

GEDCOM-X comes into its own when you are integrating directly with FamilySearch APIs, or working inside a project that has chosen it as its exchange format - and it is the better export when your data leans on evidence and conclusions, because classic GEDCOM has nowhere to put them. For sending a tree to another genealogist in 2026, though, expect them to ask for a GEDCOM.

For uploading to GEDminer specifically, any of them is fine: GEDCOM and GEDCOM X, JSON or XML, all import. Prefer whichever your software exports most completely.

Yes, in both of its serialisations. GEDminer reads GEDCOM X as JSON and as XML, alongside classic GEDCOM 5.5, 5.5.1 and 7. Drop a .json or .xml GEDCOM X file on the upload box and it is detected and parsed like any other tree - the format is recognised from the contents of the file, not its extension, so you do not need to tell us which one you have. A GEDCOM X file inside a .zip is found too.

The two forms import identically. GEDCOM X is one data model with two ways of writing it down, so the same tree exported as JSON and as XML produces exactly the same result here - the same people, the same families, the same sources. Export whichever your software offers.

What survives the import. Names (including alternates), sex, birth and death, occupation, census, migration and other custom facts, and source citations all come across, as do marriages and divorces.

What does not. GEDCOM X can express things classic GEDCOM cannot, and GEDminer's internal model is the classic one, so some of that is dropped rather than mangled: evidence-and-conclusion reasoning, the distinction between a person record and the personas supporting it, agents, and coverage statements. If your research depends on those, keep the GEDCOM X file as your master copy - the import is deliberately lossy in that one direction and does not pretend otherwise.

One structural difference worth knowing. GEDCOM X has no family record. Where classic GEDCOM writes a FAM that people point at, GEDCOM X records the relationships directly - a couple here, a parent and a child there - and leaves the grouping implicit. GEDminer reconstructs families from those relationships, using each child's set of parents to identify its family, so charts and kinship work the same way as they do for a GEDCOM. A child with three or more recorded parents (adoption, or a correction) is placed in one family per parent pair, which is how classic GEDCOM records the same situation.