Advanced Tools at GEDmatch: Using Segment Data and more

All my slides are always online at

The new home page has much help for new users plus messages about what's new on GEDmatch

GEDmatch is still the best place to compare your kit to DNA tests from other companies

example of the one to many comparison

Why is GEDmatch is still the best place to compare your kit to DNA tests from Ancestry or relatives tested at different companies?

- MyHeritage does not show the X

- Family Tree DNA does not show comparisons of        third parties to each other nor triangulations

- Neither shows fully identical regions (FIRs)

- and there are way more segment level tools at GEDmatch

Some of the  FREE tools that I find invaluable are highlighted

Be sure to always check that your newly uploaded kit has uploaded correctly

When uploading a new kit be sure to check if the parents are related, if they are this can make it harder to figure things out

There is a now a relationship calculator 

The free version of the One to Many shows the testing company and how many SNPs are in common between the kits

Close up: note the testing company and how many SNPs are in common between the kits and mitoYDNA has been linked to a haplogroup

Click the largest segment under autosomal to get the one to one comparison for that match, same for X

How to get the image only?

Check graphic only on the form

If you and a DNA relative are both tested at Ancestry, you can upload to GEDmatch to see the actual segment data

Viewed as an image, the HIRs (half identical regions) show as blue bars and the FIRs (fully identical regions) show as green bars

Why is this useful? Well to have fully identical regions with a relative you need to be related on both your mother's and father's sides. Full siblings, 3/4 siblings, double first cousins

3/4 siblings HIRs + FIRs = theoretically about 2500 

example known 3/4 siblings: 2267.7 + 533.8 = 2801.5

Most comparisons will have only blue bars and no green bars of any significant length

Another option on the one to one form is to show only the FIRs? doubly related people like full siblings, 3/4 sibs, double first cousins will all have these

Normal one-to-one image chr 1-8

At the bottom of the image comparison are the numbers

The X is often important for figuring out relationships. 

Sisters who share a Dad will share a full X, see

Two HALF sisters

Two full sisters

The X chromosome is a separate comparison

Note that here we are getting both numbers and image

Be sure to check the Prevent Hard Breaks on the X form

Tag groups make the one to many more useful, see

To see your tag groups check either One or All in Tag Groups

The one to many with tag groups for a close cousin tells me quickly how they are related

To set up or edit your tag groups click on the

VIEW/EDIT next to your profile summary


The next page has a set of tabbed headings; click on Tag Group Management


Give the group a name in description and a color by selecting one from the color chart

The shared option is not yet implemented but you can transfer the group to another account

People who match both kits, or 1 of 2 kits

Some of the Tier 1 (so PAID) tools that I find invaluable are highlighted

Combine multiple kits into 1 superkit

you can make a kit which combines all your test results from different companies

Find common ancestors in the trees of your DNA matches - here are my results

Click on PTH to see the below, the 3G or whatever G shows the descent for that one person from the common ancestor 

In Tier 1 you can check the checkboxes from the one to many or kits that match 2 kits and then click on visualiztion oprions to get to the MULTI KIT ANALYSIS

You can do a matching segment search for just the selected kits

Even better is a triangulation for just the selected kits

My Compact Chromosome Browser

Autosomal Matrix

The 3D chromosome browser includes multiple matrices, autosomal. X, and number of segments

Tier 1 members have a more accurate One to One for checking on the validity of small segments

A normal one to one

My and my double 3rd cousin, shared Jewish ancestral couple

The Q matching One to One

Q pile ups: My aunt and my new 3rd cousin

SNP density: My other aunt and my new 3rd cousin

Recently a Norwegian DNA match to Dad with a deep family tree found that he is my 12th cousin twice removed

His single segment match to my Dad and my brother is in a pile up area with about 100 or so matches on the various sites

 Actually GENI figured it out for us.


So now I wonder if those many other matches on this 12cM pile up area are also descended from this ancestor

Could I investigate using thegranularity on

Segment Searches (Tier 1) ?

OOPs, I see cousins on both Dad's paternal and maternal side. How might I ensure that those overlapping segments triangulate?

This way found 64 segments. My brother has this same pile up ....

A phased kit of the DNA my brother got from my father can be used!

Much better, only 54 and only his maternal cousins now

The GEDcom tools were the first apps on GEDmatch before autosomal DNA, they are still useful

Basic clustering has changed a little, older version here:

but the new tools include some new clustering from Genetic Affairs!

Can software figure out the family tree from the shared DNA?

AUTO Kinship

The result has to be downloaded

After you download it and unzip it click on the folder Autokinship then on the HTML file autokinship to see a long page in your browser: first the clusters

My auto kinship clusters

one endogamous population grandparent, and another missing from the testing community

Since so many of my MUNSON cousins are tested ...  what would autokinship came up with for that cluster 2 green box?

Lauritz + Josephine Monsen





Pretty accurate. I have identified which child of my great great grandparents each match is descended from. Only the last one is not, he is actually descended from a sister of Josephine's


A closer look at my cousins with the one generational correction


Next is a matrix of how many cM  they each share with each other

And finally there is a list of shared segments that met your criteria

Tim Janzen did a great Rootstech talk about these new features at

Shall we look at the auto tree for my endogamous cluster?

Here are the few trees created for cluster1 - the problem is not enough kits have linked trees on GEDmatch

Gugenheimer and Thannhauser are known ancestral lines,  not Shadur 

Can this

autokinship tool

help in unknown parentage cases?