What GedMend will and won't do — and how to check

Software that touches your irreplaceable files should not ask to be believed. Here is what GedMend does not do, and how to check the things it says it does — on your own files, before paying anything.

Last updated 1 September 2026

Every developer says they test their software. That is worth nothing to you, because you cannot see the tests, and it is being said by the person selling you the thing.

So this page is built the other way round. It states plainly what GedMend does not do, and then hands you the means to check the rest yourself: everything except the final export is free and never expires, and every export prints arithmetic you can verify against files whose contents you already know. Neither requires taking our word for anything.

What GedMend will not do

This list is longer than most products publish. That is deliberate: the failure cases are what you actually need to know before trusting software with a file you cannot replace.

Deliberate limits

It does not merge source records. If both of your files describe the same parish register, the merged file will list it twice. No tool can safely tell that two descriptions of a register are the same physical thing, and collapsing them would repoint every citation that relied on them. That tidying belongs in your main program, where you can see them side by side.
A citation cannot be tied to one side of a resolved conflict. When two files disagree on a date and you choose one, the other file's citation is kept — nothing is dropped, nothing is loosened onto the person, and nothing is altered to look like support for the value you kept. It stays on the event, because the format attaches a source to an event and not to a date. The change report records which value you chose. If you need both values and both citations kept distinct in the file itself, choose keep both: that writes two separate event structures, each with its own citation. (More on citations.)
Some duplicates may have survived. Any pair you deliberately separated stays as two records — and so does any pair you never reached. GedMend cannot tell a careful decision from an oversight, so it lists the pairs it is unsure about and leaves the judgement to you.
There is no automatic merge mode. You confirm every merge, individuals and families alike. This is the product, not a missing feature.
Family records get keep-or-discard, not per-field resolution. Individuals have full side-by-side conflict resolution. Family-level records do not, in this version.
Two files at a time. Not three, not a folder.
It will not de-duplicate within a single file. It reconciles two files against each other.

Things it is not

Not a genealogy program. No charting, no research hints, no tree editing, no DNA features. It is the step you run before your main program merges anything.
Not a validator or a repair tool. Clean structure is a byproduct of how the output is written. Problems already present in your input are surfaced, not silently fixed.
It does not manage your media files. Links to images are preserved; the image files themselves are not copied or relinked.
It does not read the proprietary database formats of other programs. It works through the standard exchange format, which every program can import and export.

Formats and platform

Reads GEDCOM 5.5, 5.5.1 and 7.0; writes 5.5.1, with a compatibility 7.0 export. A 5.5 file is written back as 5.5.1 — 5.5 is read-only.
Windows only — Windows 10 version 1809 or later, 64-bit, from the Microsoft Store. A Mac version is planned, but it is not a promise and there is no date.
English only in this version, though the data handling is not: accents, non-Latin scripts and non-Gregorian calendar dates are handled and preserved.

A known defect, published rather than waited for

A GEDCOM 5.5 file written back as 5.5.1 can carry constructs that 5.5.1 removed. GedMend reads 5.5 but does not write it, so a 5.5 file comes back labelled 5.5.1. The trouble is that 5.5.1 withdrew several things 5.5 allowed — a photograph embedded in the file itself, a media format recorded on the object rather than on the file, an age on an engagement, and a few date forms. Those lines are carried through faithfully, so nothing of yours is lost; what is wrong is the label. A strict validator will report them, and it will be reporting lines GedMend did not write.

Measured, on public test files, with the free validator you can run yourself at ged-inline.org. Our 5.5.1 output of Heiner Eichmann’s allged.ged carries nineteen such lines that the input is not reported for: six media formats and six notes recorded on a multimedia object, and seven file references with no format — which is every file reference in the file. If you run that validator yourself you will see five of each and no more: it suppresses long runs of identical messages, so its report shows fifteen. The nineteen comes from counting the output directly. Every one of those lines came from the input unchanged; what changed is the version they are being judged against. The TGC551LF torture file adds a status without a date, dates written B.C., and LDS status values, in the same shape.

GedMend now tells you at export when your file contains such constructs, and names them — for allged.ged it reports “this file uses a media format on the record (OBJE.FORM) and a note on the multimedia record (OBJE.NOTE)”. The proper fix is a converter, and it is not written.

Check it yourself, on your own files

Everything except the final export is free, with no time limit and nothing to expire. That is not a trial gimmick — it is what makes the paragraphs above checkable. Load your two real files, work through the matches, resolve the conflicts, read the change report, and decide whether we deserve the export fee after you have seen what we would write. Your originals are read-only throughout, so there is nothing to undo.

Two things are worth checking while you are in there, both against files whose contents you already know.

The count equation. Before anything is written, the preview shows: people in File A, plus people in File B, minus the pairs you confirmed, equals people out. Every confirmed pair removes exactly one duplicate, so the arithmetic comes out exactly or not at all. The same check runs for families. If it does not balance, GedMend says so rather than writing the file quietly.

The citation arithmetic. Every export writes a change report — in both HTML and plain text — giving per-person figures like Citations: A=2 B=3 merged=4. Add the inputs, subtract the ones that folded because they were identical, and compare. A merged count lower than the larger of the two inputs would mean evidence was discarded; that has a name, and it is a bug.

That headline figure counts every citation on the person, including the ones attached to a birth, marriage or death rather than to the person directly — which is how most programs write them. A second figure in brackets gives the count attached to the person alone. When the two differ, it is because your evidence hangs off the events, and nothing is wrong.

This is a better test than any prepared example could be, because it is your tree: you already know which two people are the same person and which source you cited twice. That is a stronger form of assurance than any statement on this page.

What GedMend will do

Stated compactly, since the rest of the site covers it in detail:

Your original files will not be changed. They are opened read-only; the result is always a new file you name.
No files are changed until you click Confirm & Export.
Every source citation is preserved — kept and merged, duplicates collapsed only when identical, never stripped.
Deterministic, explainable matching — no AI. The same two files always give the same result, and every proposal shows its reasoning.
Catches duplicate families, not just people — you confirm each merge.
Never corrupt your tree: the round-trip is lossless, including the unknown and custom tags other programs wrote. After a merge every reference in the input still resolves.
GedMend decodes both encodings correctly, and warns you upfront when the two files disagree so you can check the accented names.
A change report is saved listing every match, field decision, and citation merged — in both HTML and plain text.
Your genealogy data never leaves your machine — there is no network code of ours in the program. The one exception is deliberate and yours to trigger: choosing Buy hands a link to Windows, which opens the Microsoft Store to take payment. Your files are not involved.
Everything is free — load, review, resolve, see the report; export is a one-time purchase. Nothing expires.