Which DNA Test Should You Take? A Plain-English Guide

Autosomal, Y-DNA or mitochondrial? Ancestry, MyHeritage, 23andMe or FamilyTreeDNA? What each test can and can't tell you, and how to get the most for your money.

5 min read

DNA testing has become one of the most powerful tools in family history, but the choices can be confusing. Different tests look at different parts of your DNA, and different companies have very different databases of people to match you with. Here's how to choose.

First, what do you want to learn?

Most people take a DNA test for one of three reasons:

• To find relatives and confirm or extend their family tree. This is where DNA is most useful for genealogy.
• To see an "ethnicity estimate", the percentages and map of where your ancestors may have come from.
• To answer a specific question, such as identifying a biological parent, proving two families are related, or tracing a surname line.

Your goal decides the test.

The three kinds of DNA tests

Autosomal DNA: the test almost everyone should start with

Autosomal DNA comes from both parents and all of your recent ancestors on every line. It's what AncestryDNA, MyHeritage DNA, 23andMe and FamilyTreeDNA's Family Finder test. It finds cousins reliably to about the third cousin level, and often further, out to roughly five or six generations.

Because you inherit a random half of each parent's DNA, you share less and less with more distant relatives. You'll share DNA with every second cousin, about 90 percent of third cousins, and only about half of fourth cousins. Beyond that, a match is possible but not guaranteed.

Anyone can take an autosomal test, male or female.

Y-DNA: the direct paternal line

Y-DNA is passed from father to son nearly unchanged, so it follows the surname line back for centuries. Only men can take it. A woman can trace her father's line by asking her father, a brother, or a paternal uncle or male cousin with the surname to test. Y-DNA testing for genealogy is offered mainly by FamilyTreeDNA. See Y-DNA and Surname Projects.

Mitochondrial DNA (mtDNA): the direct maternal line

Mitochondrial DNA is passed from a mother to all of her children, so it follows your mother's mother's mother's line. Everyone can take it. It changes very slowly, which makes it great for deep ancestry but less precise for recent genealogy. A full-sequence mtDNA match could share an ancestor in the last few generations or a thousand years ago. It's most useful for specific questions, such as testing whether two women descend from the same mother.

Comparing the major companies

• AncestryDNA: by far the largest database, which means the most matches. Its matches link to family trees, which is enormously helpful for figuring out how you're related. You can't upload results from other companies to Ancestry, so it's usually the best first test for U.S. research.
• MyHeritage DNA: a large database with particular strength in Europe, useful if you have recent European immigrant ancestors. It no longer accepts uploads from other companies, so to appear in its match list you need to test there.
• 23andMe: known for health reports as well as ancestry. Its relative-matching is useful but has fewer attached family trees, and it doesn't accept uploads from other companies. The company went through bankruptcy and a sale in 2025, which reminded many customers to review its privacy settings.
• FamilyTreeDNA: the main company for Y-DNA and full mtDNA tests and home to thousands of volunteer-run surname and regional projects. It also offers an autosomal test (Family Finder).

Prices change often, and every company holds sales around holidays like Mother's Day, Father's Day, Black Friday and the winter holidays. If you're not in a hurry, wait for one.

Fishing in more than one pond

Every company lets you download your "raw data" file. For years, researchers uploaded that file to other companies to find more matches for free. That door has mostly closed: MyHeritage stopped accepting uploads in 2026, Ancestry and 23andMe have never accepted them, and other companies' policies change often. Check a company's current upload policy before you count on it.

• GEDmatch is an independent site built for comparing people who tested at different companies. Uploading is free, and it has tools serious researchers love.
• To be in another company's database, you'll generally need to buy its test. If you're working on a hard problem, testing at two companies can be worth it.

Ethnicity estimates: interesting, not precise

Ethnicity estimates compare your DNA to reference groups of modern people. They're good at continental-level ancestry (European vs. African vs. East Asian, for example) and often surprisingly good at some regions, but they're estimates. Results change as companies update their reference panels, and different companies give different answers for the same person.

Don't change your family tree based on an ethnicity percentage. A small or missing percentage doesn't prove or disprove an ancestor; your matches are the real evidence.

Who in the family should test?

• Test the oldest generation first. Your parents, grandparents, aunts and uncles each carry DNA from ancestors that you didn't inherit. A test from an 85-year-old great-aunt can be worth more than tests from five cousins.
• Test both sides. If one parent tests, you can sort your matches into maternal and paternal sides instantly.
• Test for a purpose. To prove a hypothesis, test descendants of the people involved, through different children if you can.

Privacy and surprises

Before you test, think about two things.

Privacy. Read the company's privacy policy and settings. You can usually choose whether to appear in match lists, whether to allow research use of your data, and whether your data can be compared with law-enforcement uploads. GEDmatch and FamilyTreeDNA let users opt in or out of law-enforcement matching.

Surprises. DNA doesn't keep family secrets. Testers regularly discover unknown half-siblings, adoptions, or that a parent isn't the biological parent they believed. These discoveries are common enough that you should be prepared for one, especially if you ask relatives to test. Many companies and support groups offer resources for people handling an unexpected result.

What to do when your results arrive

1. Attach your test to your family tree (even a small one) so matches can see how you might connect.
2. Start with your closest matches. Look at their trees for shared surnames and places.
3. Use shared matches to sort people into family groups.
4. Message politely. Many matches never log in again, but those who do are often eager to compare notes.

When you're ready to take it further, read Using DNA Matches to Break Through Brick Walls.