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What is a GEDCOM file, and how do I open or convert one?

The file format that moves a family tree between programs — what it is, the versions and encodings, and how to import, edit and export one.

Guide · Updated July 2026

GEDCOM (GEnealogical Data COMmunication) is the plain-text file format genealogy programs use to exchange family-tree data. A GEDCOM file, ending in .ged, stores people, families, events and notes as numbered levels and four-letter tags. To move a tree between programs, you export it as GEDCOM from one and import it into another — which is why almost every genealogy application can read and write it.

What is inside a GEDCOM file

GEDCOM is human-readable text. Each line has a level number and a tag: 0 @I1@ INDI opens an individual record, and 1 BIRT nested beneath it opens their birth event. Because it is an open, plain-text format, it is the reason you are not locked into one program.

GEDCOM 5.5.1 vs 7.0

5.5.1, published in 1999, is still what nearly every program reads and writes, so it remains the safe choice for moving a tree. 7.0, released in 2021, requires UTF-8 encoding and cleans up how media is handled, but industry support is still partial. If you are handing a file to someone else, export 5.5.1 unless you know their program reads 7.0.

Encodings, and why a tree can look scrambled

Older GEDCOM files use a range of character encodings, and reading one with the wrong encoding turns accented names into garbage. The common ones are ANSEL (an older standard that stores the accent before the letter), UTF-8, UTF-16, and Windows-1252. A good importer detects the encoding automatically; if it does not, Scandinavian, German, Polish and French surnames come in scrambled or accent-stripped.

How to import, edit and export one online

  1. Export from your current program as GEDCOM 5.5.1.
  2. Import it. AncestorOS imports GEDCOM 5.5.1, automatically detecting ANSEL, UTF-8, UTF-16 and Windows-1252, and handling the full 5.5.1 date grammar (approximate dates, ranges, periods, and Julian/Hebrew/French Republican calendars, plus dual-year dates like 1699/00). Large files import in batches.
  3. Edit in the browser — add people, events, places and relationships.
  4. Export clean GEDCOM 5.5.1 (UTF-8) when you want to move the tree again.
One honest limit to know before you import: source citations (SOUR) and media objects (OBJE) inside a GEDCOM are not imported — they are reported and skipped. Keep your original file. Names, events, dates, places and the family structure transfer.
Glossary: GEDCOM Glossary: ANSEL GEDCOM import & export

Frequently asked

GEnealogical Data COMmunication. It is the plain-text file format (.ged) genealogy programs use to exchange family-tree data.
Use 5.5.1 for moving a tree between programs — nearly every application reads it. GEDCOM 7.0 (2021) is newer and UTF-8-only, but support across programs is still partial.
Almost always a character-encoding mismatch — typically an ANSEL file read as plain text. ANSEL stores the accent before the letter, the opposite of Unicode. An importer that detects ANSEL renders the accents correctly.
It depends on the program. AncestorOS imports names, events, dates, places and family relationships, but does not import GEDCOM SOUR (source) or OBJE (media) records — it reports and skips them, so keep your original file.
Yes. A web-based tool like AncestorOS lets you import a GEDCOM, edit it in the browser on any operating system, and export clean GEDCOM 5.5.1, with nothing to install.

Put it into practice

AncestorOS gives you Evidence Explained citation templates, Genealogical Proof Standard–aligned research logs, GEDCOM import and export, and DNA match tracking in one web-based workspace.

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