How to Use GEDmatch DNA Matching Tools (One-to-Many, One-to-One, Segment Search)

How to Use GEDmatch DNA Matching Tools (One-to-Many, One-to-One, Segment Search)

Before You Begin

To use GEDmatch's matching tools, you need:

1.   A GEDmatch account with at least one uploaded DNA kit.

2.   Your kit must have finished processing (typically 24–48 hours after upload). If your kit is still processing, matching tools will not be available yet.

3.   Your kit must have a Public access status. Kits set to Private will not appear in search results and cannot be used with most tools.

For more on kit status settings, see our article on Managing Your DNA Kits.

 

One-to-Many: Finding Your Match List

The One-to-Many tool is where most users start. It generates a list of your closest genetic matches across the GEDmatch database.

How to use it:

1.   Log in to gedmatch.com.

2.   Find the "One-to-Many DNA comparison" section on your dashboard.

3.   Your kit number should appear automatically. If you have multiple kits, select the one you want to use.

4.   Click the green "SUBMIT" button.

5.   Your match list will appear, showing your closest genetic matches ranked by the amount of shared DNA.

Reading your One-to-Many results:

      Kit Number: The unique identifier for each match.

      Name/Alias: The name or alias the match has set for their kit.

      Total cM (centimorgans): The total amount of DNA shared with you. Higher values indicate closer relationships.

      Largest Segment cM: The size of the largest single shared segment. Larger segments are more likely to indicate recent common ancestry.

      Gen (Generations): An estimated number of generations to your most recent common ancestor. This is an estimate, not a certainty.

      Email: If the match has chosen to share their email address, it will appear here for you to contact them.

Tips:

      Matches are sorted by the amount of shared DNA by default, with closest matches at the top.

      The ability to select and compare multiple matches from your One-to-Many results is a Tier 1 feature. Free users can view their match list but cannot multi-select.

      If you see no matches, your kit may still be processing. Check back after 24–48 hours.

 

One-to-One: Comparing Two Specific Kits

The One-to-One tool compares two specific kits in detail, showing exactly where on each chromosome the two individuals share DNA.

How to use it:

1.   On your GEDmatch dashboard, find the "One-to-One Autosomal DNA comparison" section.

2.   Enter your kit number in the first field.

3.   Enter the kit number of the person you want to compare with in the second field.

4.   Click the green "SUBMIT" button.

5.   The results will show a chromosome-by-chromosome breakdown of shared DNA segments.

Reading your One-to-One results:

The results display a table showing each chromosome, the start and end positions of shared segments, the length in centimorgans (cM), and the number of shared SNPs.

A visual chromosome browser may also appear, showing colored bars where DNA is shared.

Important notes:

      The kit you are comparing against must have a Public or Research access status. Kits set to "Research" can be used in One-to-One comparisons by other members, but will not appear in One-to-Many results.

      If a kit number returns an error saying it is not available, the kit owner may have set their kit to Private, or the kit number may be incorrect.

 

One-to-One X DNA Comparison

There is a separate One-to-One X DNA comparison tool located immediately below the Autosomal One-to-One tool. This tool compares only the X chromosome.

      The X DNA tool only shows X chromosome matches. If you see no results, it does not mean you are not related — it means you do not share X chromosome DNA with that person.

      X DNA inheritance follows specific patterns: men receive their X chromosome from their mother only, while women receive one X from each parent. This can be useful for narrowing down which side of the family a match comes from.

Common confusion: Some users accidentally use the X DNA tool instead of the Autosomal tool, resulting in unexpectedly few or no matches. Make sure you are using the Autosomal comparison tool for a full comparison.

 

The Segment Search tool allows you to search for other kits that share DNA on a specific chromosome segment. This is a Tier 1 tool for paid subscribers.

How to use it:

1.   On your dashboard, find the Segment Search tool.

2.   Enter the chromosome number and the start/end positions of the segment you want to search.

3.   Submit to see a list of kits that share DNA in that region.

This tool is useful for identifying clusters of related individuals or triangulating common ancestors.

Note on Segment Search results:

If a person is a match by One-to-One comparison but does not appear in a Segment Search of the same region, this can happen due to matching thresholds. The Segment Search may use different minimum segment size or SNP density thresholds than the One-to-One tool.

 

AutoSegment Split (New Feature for Tier 1 Subscribers)

AutoSegment Split is a newer feature that automatically groups your matches by shared chromosome segments. This helps identify clusters of related individuals who likely share a common ancestor on a specific line. Visit the GEDmatch Education page for guides and blog posts on how to use AutoSegment Split.

 

Understanding Shared DNA and Relationships

The amount of shared DNA (measured in centimorgans, or cM) can help estimate how you are related to a match:

      ~3,400 cM: Parent/child or identical twin

      ~2,500–2,900 cM: Full sibling

      ~1,700–2,100 cM: Grandparent, grandchild, half-sibling, aunt/uncle, niece/nephew

      ~600–1,100 cM: First cousin, great-grandparent

      ~200–600 cM: Second cousin range

      ~50–200 cM: Third cousin range

      <50 cM: Distant cousin (4th cousin or more distant)

These are approximate ranges. The actual relationship can vary. For more detailed relationship prediction, tools like the Shared cM Project can help estimate possible relationships based on the total shared DNA.

 

Frequently Asked Questions

Why do I see "No matches" when I know I have relatives?

Your kit may still be processing (allow 24–48 hours). Also verify that your kit is set to Public access status, not Private. If your kit is in "Private" or "Research" mode, it may not appear in all search results.

What does "Research" kit status mean for matching?

Kits set to "Research" can be found and compared by other users in the One-to-One comparison tool, but they will not appear in One-to-Many match lists. If you want to be found by your matches, set your kit to one of the "Public" options.

Can I see matches from a specific testing company?

GEDmatch combines all uploaded kits into one database regardless of which testing company the data came from. You cannot filter matches by testing company, which is one of the key benefits of using GEDmatch — it casts a wider net by comparing across testing companies.

Why did my match disappear from my list?

The match may have changed their kit access status to Private, deleted their kit, or deleted their GEDmatch account.

What is a Superkit?

A Superkit is created by combining two or more DNA kits from the same person (e.g., one from Ancestry and one from 23andMe) into a single merged kit for better matching coverage. This is a Tier 1 feature for paid subscribers.

 

Troubleshooting Matching Issues

Tools say "no kits uploaded" even though I uploaded my DNA:

Make sure you are logged in with the same email address and login method you used when you uploaded your kit. If you used a Google or Yahoo social login originally but are now logging in with the email form (or vice versa), you may have landed on a different, empty profile. Log out and try the other login method.

One-to-Many runs but shows zero matches:

Your kit may still be processing (allow 24–48 hours after upload). Also check that your kit status is set to Public — kits in Private or Research mode may not generate a match list.

Kit number gives an error when entered in One-to-One:

The kit you're trying to compare with may be set to Private, which blocks all comparisons. Ask the kit owner to change their status to Public or at least Research (which allows One-to-One comparisons). Also double-check the kit number for typos.

A match appeared before but is gone now:

The other person may have changed their kit to Private, deleted their kit, or deleted their GEDmatch account. GEDmatch cannot restore matches that other users have removed.

Select feature in One-to-Many doesn't work:

The ability to select and compare multiple matches from One-to-Many results is a Tier 1 feature. If you are a free user, this function will not be available.

 

Learn More

For more detailed guides, video tutorials, and blog posts about GEDmatch tools, visit the Education page on the GEDmatch website: https://www.gedmatch.com/education



    • Related Articles

    • How to Upload DNA Files to GEDmatch (All Testing Companies)

      What You Need to Know Before Uploading GEDmatch accepts uploads of Autosomal DNA raw data files from most major DNA testing companies. GEDmatch does not perform DNA testing — you need to first take a DNA test with a testing company (such as ...
    • Tier 1 Subscription: Pricing, Features, Cancellation & Payment Management

      What is Tier 1? GEDmatch offers two membership levels: • Free: Includes access to basic genealogy tools, which are sufficient for most users. Free tools include One-to-Many matching, One-to-One comparison, and basic admixture calculators. • Tier 1 ...
    • What is GEDmatch?

      We are a genetic genealogy site that allows people to find their genetic relatives. What is unique is that we allow people to upload their DNA profile from over 20 different providers (profiles uploaded from 23andMe, Ancestry, FamilyTree DNA, ...
    • Troubleshooting Common GEDmatch Errors

      Site Access Errors 403 Error / "Bot Detection" Block Symptom: You receive a 403 error or a message indicating you have been identified as a bot and cannot access the site. Cause: GEDmatch has security measures in place to prevent automated access. ...
    • Managing Your DNA Kits: Finding Kit Numbers, Kit Status, and Resolving Issues

      Finding Your Kit Number Every uploaded DNA file on GEDmatch is assigned a unique Kit Number (e.g., AB1234567). You need this number to use matching tools and to share with others for comparison. Where to find it: 1. Log in to your GEDmatch account at ...