What Is GEDMatch? How Does It Work?
Updated on April 11th, 2019
As genetics science and technology develops more and more services that use autosomal DNA test data are being offered to consumers. One unique offering is GEDMatch that can use results from other DNA testing kits to provide additional information about potential family members.
Here at YourDNA.com, we have looked into this product and done the research so you can decide if using it is a good idea for you and your family.
What Is GEDMatch?
GEDMatch is a genetic genealogy website that specializes in finding very close and distant relatives using DNA.
It works by using the results from an at-home DNA test and is compatible with tests from numerous DNA testing companies.
GEDMatch has been offering this relative match service since 2010 1. Since then 23andMe, Family Tree DNA and Ancestry.com have launched similar services of their own that are available to people who have taken their DNA tests.
The difference is GEDMatch can find relatives from any of those commercial DNA companies.
What Is the Purpose of GEDMatch?
The founders of GEDMatch, John Olson and Curtis Rodgers, have stated that it’s primary purpose is to assist both amateur and professional genealogists.
That’s a fairly broad purpose that doesn’t really address what GEDMatch is capable of doing.
The main purpose of GEDMatch is to connect people to their relatives using DNA test results. Once relatives have been identified, you can contact them directly via email.
It’s one of the most popular genealogical analysis tools available today but there are limitations. Most significantly, you’ll only be able to find relatives that 1.) have used a DNA testing service and 2.) uploaded their DNA data in GEDMatch.
GEDMatch also has a secondary purpose that the creators may not have anticipated. In April 2018, a member of law enforcement in California used GEDMatch to find a suspect connected to the Golden State Killer serial killer case from the 1970s and 1980s 2.
After this successful identification, GEDMatch is now being used by law enforcement around the country to find criminals and help victims of crimes. It’s even been called the de facto DNA and genealogy database for members of law enforcement.
Why Use GEDMatch?
GEDMatch is used by people who are interested in identifying where their relatives are from. It can also be an invaluable tool for people who are trying to connect with relatives and compare family trees.
This could simply be a matter of curiosity or something of greater importance.
For example, people who were adopted and know nothing about their biological family can use GEDMatch to see where relatives live 3. They may discover a number of relatives nearby that they can build a relationship with.
As mentioned above there’s a distinct advantage to using GEDMatch over the tools provided by DNA testing companies. Namely, you can see relative matches no matter what DNA test they used.
In some cases, GEDMatch’s DNA segment data processing is more robust and will catch matches that weren’t found through the DNA testing company.
Users also tend to prefer GEDMatch’s direct contact through regular email versus the DNA testing company’s platform.
Is GEDMatch Safe?
Many people have legal and privacy concerns when using any type of DNA tool. This is understandable since DNA is extremely personal and is also connected to sensitive medical information.
With GEDMatch, safety and security of information has been a common concern right from the start.
GEDMatch is set up to be an open database. This means anyone can access it if they create an account.
This is the first security concern. The fact that volunteers are processing information and updating the database is another related safety consideration.
The second security concern is that personal information will be displayed. An email address and the name used in connection with the DNA testing kit is needed to create an account.
Therefore personal information is connected to the DNA results and shows up in the reports. If you choose to use GEDMatch you have to accept that you will be putting a personal email address out there for others to contact you.
In an effort to protect personal information you may want to create a new email account specifically for use on GEDMatch.
There’s also the unique issue of law enforcement using GEDMatch to identify suspects. While most people will agree there is a huge benefit to this, just as many people don’t like the idea law enforcement could access their own DNA data.
Some researchers have also voiced concern over the possibility that their data could be sold. The fear is that GEDMatch will wind up like findagrave.com, which sold to Ancestry.com.
Once the site was sold, the users no longer had access to their accounts but Ancestry.com did.
Is GEDMatch Free?
GEDMatch is a free genealogy website to a certain degree. In order to parse any information out of the GEDMatch tools, you must first have paid for an at-home DNA testing kit.
The GEDMatch website is able to provide tools for free because it’s operated by volunteers 4. The volunteers maintain the site, analyze the raw data and provide the results at no charge.
GEDMatch also offers premium tools for a fee.
How to Create a GEDMatch Account
Creating a GEDMatch account is easy. To create an account:
Step 1. Fill out the User Registration Form using your real name, an alias (optional), email address and password with at least six characters that include at least one symbol or number.
Step 2. Check your email for the registration confirmation code. You must copy the code and paste into a field on the GEDMatch website then click the confirm button.
Step 3. Upload the autosomal raw DNA data (GEDCOM) to get results sent to your account and use the analytical tools.
You can update your account information and DNA resources profile at any time.
How to Upload DNA Data to GEDMatch
In order to find relatives, GEDMatch must process the raw results of autosomal DNA test data that the user uploads.
- Download the autosomal raw DNA data from your DNA testing company to your computer.
- In the file uploads section of your GEDMatch account, select your DNA testing company. If you tested with multiple DNA testing companies just pick one to upload.
- Do not unzip the file before uploading.
- Fill out the form fields as best you can.
- Click the “choose file” button to select the DNA data.
- Click the upload button.
- Wait for the information to upload before leaving the page. This can take several minutes. Once the upload is complete you should be taken to another page and see the verification that the upload has finished.
*Family Tree DNA users will have to upload the Family Finder and X-DNA data files.
Once the data has been processed you’ll receive a notification on the homepage of your GEDMatch account. Unfortunately, the DNA raw results aren’t processed immediately.
It can take up to a few weeks for GEDMatch to process the information. Once the results are in, you can use the tools to learn more and put the information into a DNA match spreadsheet.
GEDMatch Genealogical Analysis Tools
Once your DNA data is uploaded you can begin playing around with the GEDMatch tools. These tools can be used to find relative matches, see the amount of DNA that’s shared, compare DNA chromosome by chromosome, triangulate matches and much more.
GEDMatch tools can be complex for novice researchers. There’s also a lot of information to parse through, but luckily the GEDMatch tools have a lot of filters.
GEDMatch has what they call Tier 1 tools, which are enhanced versions of the One-to-Many tool and the One-to-One tool as well as a few additional tools that cost a small fee.
How to Use the One-to-Many Tool on GEDMatch
The One-to-Many tool is a match list based on shared chromosome segments. To use this tool:
- Click on the One-to-Many matches link in the Analyze Your Data section.
- Enter the kit number you were assigned by GEDMatch.
- Click the Display Results button.
- You’ll then get a list of DNA matches from the GEDMatch database in the form of a table. The list is organized from closest to least close match represented as total cM (centimorgan). Centimorgan measures DNA information in a chromosome to determine genetic linkage.
- From here, there are a number of things you can do:
- Click on the L of an entry to see a list of that individual’s matches.
- Click on the A of an entry to see a one-to-one autosomal comparison with an individual. This is the best indicator for a relative match.
- Click on the X to see a one-to-one comparison of an individual’s X-DNA.
- Within the table, you can see a lot of top-level information, such as:
- The DNA testing kit that the match used (Kit Nbr column)
- How many generations are between you and the match (Gen column)
- The largest cM segment.
- The tool will color code new matches (within last 30 days) green.
- To improve the accuracy of potential relative matches set the Total cM to a minimum of seven.
- Filtering boxes allow you to narrow the list.
- You can make custom matching criteria.
Keep in mind that GEDMatch uses batch processing to create the One-to-Many report. Because of this, there could be people on the list who aren’t actually a relative.
How to Use the One-to-One Tool on GEDMatch
The One-to-One tool is used to verify a relative match found using the One-to-Many tool by comparing your DNA to another person.
The tool can be accessed in one of two ways:
- By clicking on the A or X for an individual in the One-to-Many report.
- Selecting the One-to-One link on your account home page then entering the kit numbers for the people you want to compare.
In the One-to-One report, you can look for exact chromosome segment matches including the largest segment that’s shared and the total number of matching segments. Each segment will be represented along with the total cMs.
The higher the total is the closer you are related. A lot of small shared segments suggest you’re related in more than one way.
If you’re a visual learner you can choose to show the data in a graphic bar.
Once a match is verified, you can then email the individual to make a connection, share information and compare family trees.
Other Tools Available on GEDMatch
The One-to-One and One-to-Many aren’t the only GEDMatch genealogical analysis tools.
Other tools include:
- Matching Segment Search Tool
- Relationship Calculator – This only works with X chromosome matches.
- Genetic Distance Calculator
- Ethnicity Calculator
- 3D Chromosome Browser
It can take some time to learn how to use all of the GEDMatch tools. If you need assistance YourDNA.com can help.
Does GEDMatch Offer DNA Testing?
At this time GEDMatch does not offer DNA testing. It is a third party site with genealogical analysis tools that use autosomal DNA test data from certain commercial DNA companies.
In order to use the GEDMatch tools, you’ll need to buy a kit from a separate DNA testing company.
Which DNA Testing Company Should I Use?
GEDMatch is compatible with several DNA testing companies. You can upload data from 23andMe, Ancestry.com and Family Tree DNA. Which of those three commercial DNA companies you decide to use is up to you.
Each DNA testing company offers something unique at a different price point.
- The 23andMe Health + Ancestry DNA test provides insight on whether you have certain genetic mutations that increase might risk for diseases or can be passed down to children.
- Ancestry.com’s DNA test is an extension of its genealogy research service that provides historical insights alongside DNA results.
- Family Tree DNA offers separate Paternal and Maternal Ancestry tests that show how family members migrated throughout the world.
Need help selecting a DNA testing company, uploading your DNA data to GEDMatch or interpreting the results? One downside of GEDMatch is that the results are very technical and if you aren’t familiar with the scientific terminology deciphering everything can be difficult 5.
YourDNA.com can provide assistance with a variety of DNA testing tools, guide you through selecting the best DNA test and connect you with a knowledgeable genetic counselor for further information.
Wikipedia. June 2019. ↩
- The ingenious and ‘dystopian’ DNA technique police used to hunt the ‘Golden State Killer’ suspect.
Avi Selk. 28 April, 2018. ↩
- Connecting the chromosomes: Adoptees find, reunite with birth mothers through online DNA services.
Brittany Britto. The Baltimore Sun. 2017. ↩
- Tutorial: Analyze Your DNA with GEDmatch.
Shannon Combs-Bennett. June 8, 2015. ↩
- EUROGENES K36 MAPS, GRAPHS, AND DATA PART 1: UNDERSTANDING GEDMATCH ADMIXTURE TESTS.
Matthew Britt. mpbritt.com. May 7, 2018. ↩