What Is a GEDCOM File? The Complete Guide
Everything you need to know about the GEDCOM file format - its history, structure, how to create one, and what you can do with it using modern analysis tools.
GEDCOM: the universal language of genealogy
GEDCOM stands for Genealogical Data Communication. It is a plain-text file format created by The Church of Jesus Christ of Latter-day Saints in 1984 to allow different genealogy programs to share family tree data.
Almost every genealogy application - from major online tree platforms to desktop programs - can import and export GEDCOM files. This makes .ged files the closest thing genealogists have to a universal standard.
What does a GEDCOM file contain?
A GEDCOM file is structured into records, each identified by a tag:
- INDI (Individual): Names, birth dates, death dates, burial details, occupations
- FAM (Family): Marriages, divorces, parent-child links
- SOUR (Source): Citations for records, documents, and evidence
- NOTE: Free-text annotations and research notes
- OBJE (Object): References to photos, documents, and media
Each record uses a numbered level system (0, 1, 2…) to nest related information. For example, a birth date sits inside an individual record as a level-2 tag under the level-1 BIRT event.
GEDCOM versions: 5.5.1 vs 7.0
The most widely used version is GEDCOM 5.5.1, released in 1999. It handles most genealogical data well but has limitations with character encoding, multimedia, and same-sex relationships.
GEDCOM 7.0, released in 2021, modernises the format with UTF-8 encoding, better multimedia support, and extensibility. Adoption is growing but 5.5.1 remains dominant.
GEDminer supports both versions, so you can analyse files from any era of genealogy software.
How to create a GEDCOM file
Every major genealogy program can export a GEDCOM file. The option is usually under File → Export, Tree Settings → Export, or a similar menu. Online tree platforms typically offer the same option in account or tree settings.
The exported .ged file can then be opened in any compatible program - or uploaded to GEDminer for instant analysis.
What can you do with a GEDCOM file?
Once you have a GEDCOM file you can:
- Analyse it: Upload to GEDminer to get statistics, error reports, migration maps, and research suggestions
- Share it: Send to relatives or other researchers for collaboration
- Import it: Move your tree between different genealogy programs
- Back it up: Keep an offline copy of your entire tree independent of any subscription
- Compare trees: Check for overlapping ancestors with other researchers
A GEDCOM file is your data - it belongs to you, not to any software company.
Common GEDCOM problems and how to fix them
GEDCOM files are not always perfect:
- Character encoding issues: Names with accents or non-Latin characters may appear garbled in older files. Re-export using UTF-8 encoding.
- Missing sources: Many trees lack source citations. Add them in your genealogy software before exporting.
- Duplicate individuals: Merging trees often creates duplicates. Use GEDminer's Duplicate Finder to identify them.
- Broken family links: Parent-child or spousal connections sometimes get lost during transfers. Check the Integrity tab.
- Large file sizes: Trees with 50,000+ individuals may produce files over 100 MB. GEDminer handles large files efficiently in the browser.