A free GEDCOM validator that checks the things that actually break transfers between genealogy programs — malformed lines, references to records that don't exist, families that only link one way, impossible chronology, and people who appear in their own ancestry. Every finding comes with a severity and, where possible, a line number.
The validator looks for the problems that cause data loss when files move between programs: broken structure, dangling references, one-way family links, impossible dates, and likely duplicates.
Nothing is uploaded. Validation runs entirely in your browser.
Structure: the header and trailer, line syntax against the level [xref] TAG value grammar, illegal level jumps, duplicate record IDs, lines over the 255-character limit of GEDCOM 5.5.1, and CONC continuation lines in files that declare GEDCOM 7 (which removed them). References: every FAMC, FAMS, HUSB, WIFE, and CHIL pointer is resolved, and family links are checked in both directions — a person claiming a family that doesn't claim them back is how children silently vanish in imports. Chronology: deaths before births, children born before their parents (or after a mother's death), marriages outside a partner's lifetime, lifespans over 110 years, and parent/child loops. Housekeeping: missing names, unparseable dates, empty families, and possible duplicates (same name, same birth year) left over from tree merges.
Errors mean the file violates the GEDCOM structure itself and some programs will drop data. Warnings are genealogically suspicious — usually a typo in a date or a link left dangling by an edit. Notes are things worth knowing that won't break anything. The validator never modifies your file; to fix findings, edit in your genealogy program and re-check here.
Both the long-standing 5.5 / 5.5.1 standards and the modern 7.0 revision are read, in any of the encodings found in the wild — UTF-8, UTF-16, Windows-1252, and legacy ANSEL. Curious what those versions actually changed? See the plain-English guide to the GEDCOM format.
More free GEDCOM tools: GEDCOM to PDF · GEDCOM to Excel · GEDCOM to CSV · Excel to GEDCOM · CSV to GEDCOM · GEDCOM to HTML · GEDCOM to JSON · GEDCOM to XML