Best DNA Test For Siblings: Find Siblings and Half Siblings With a Simple DNA Test

article by Nicky Hoseck
May 10, 2020
A DNA test can be a life-changing experience, revealing unexpected surprises about our ancestry, ethnicity, and even our capacity to lose weight. More importantly, for some, it means discovering a whole new family! Last month, a 23andMe customer was shocked to discover that, despite having grown up as an only child, she actually has 29 siblings out there! Although Shauna Harrison’s story is unusual, the best DNA test for siblings could reveal why you and your brother don’t look alike or why your neighbor's son has the same shape and color eyes as you do!

For many people, family is the core of both their existence and their identity, so it’s little wonder many are turning to sibling DNA kits to find out just who they are and who they’re related to. So, which are the best DNA testing kits available and how can they help you find your siblings?

How Does DNA Testing for Siblings Work?

A little like a Spot the Difference competition, the best DNA test for half siblings will look at a wide range of indicators, searching for similarities and repetitions. In most cases, while siblings will share around 50% of the same genetic markers, for half-siblings it is usually only around 25%.

Although no DNA test can analyze every piece of your genetic makeup, the best DNA test for siblings offered by MyHeritage will examine 22 of the 23 chromosomes that make up your DNA and compare them to those of your possible sibling, establishing differences and similarities along the way.

Even in a full sibling, you’re not going to get a complete match and, in some instances, you might not even share the same ethnicity, even if you share the same cultural background and ancestors. Even if you and your brother have the same father and he was 100% Irish, it doesn’t necessarily mean that you will both be 50% Irish, although that’s what logic indicates.

Sometimes, the genes carrying a specific ethnicity may cross over to an individual chromosome that is inherited by one child but not the other. So, while you may take after your grandfathers and have more Italian genes, your brother may take after your grandmothers and therefore have more German influence.

If you want to find out more about exactly how the best DNA test for siblings works or simply want to read some inspiring stories from others who’ve found their families thanks to a genetic match, why not visit MyHeritage’s blog page and immerse yourself in science and sentiment?

Why Doesn’t My Sister Share My DNA?

If you think of DNA as a string of beads, and your mom’s string is made up of half Irish and half Italian beads, you can begin to understand that, when shared out, two people may not end up with the same number of Irish and Italian beads, with one person gaining on the Irish side while the other gains on the Italian.

Fundamentally, DNA isn’t passed down in large blocks, but as small beads, which means you could end up with the only African bead available from your father, while your brother ends up with none at all.  Just as you may look more like your dad and your brother more like your mom, so, at a genetic level you are distinct from one another.

Surprisingly enough, even identical twins don’t necessarily share the same DNA. In the case of fraternal twins, Kat and Eddy Abraham, the results of their DNA tests indicated that Kat had 10% less Italian and Greek genetic ancestry than her twin brother Eddy.

This example goes to show that DNA remains an extremely complex area of scientific research and that your genetic similarities with your sibling don’t always translate into a shared ancestral DNA. This is primarily due to a process known as recombination whereby the cells in an egg or sperm cell are basically a random representation of the person it originated from.

At the end of the day, however, just because your brother’s a little more Irish than you, there’s no need to ban him from the remote control for life!

#1 MyHeritage

myheritageDNA LogoWith nine billion records in its database, using MyHeritage to find your brother or sister might seem like trying to find a needle in a haystack. Fortunately, as more people get tested so the proportion of needles to hay increases in your favor and more people are getting a direct match confirming their relationship to previously unknown siblings and half-siblings.

Although not all siblings share the same DNA and no test can give 100% guarantee that you and another person are half or full siblings, testing to see if you are related can resolve a lot of underlying issues, or enable you to develop new sibling relationship that deepens your sense of self and enriches your life.

MyHeritage uses advanced genetic technology known as SmartMatch to compare people within your family tree with individuals in other people’s trees. By comparing facts, names, and other connections, MyHeritage can suggest possible relationship which can then be confirmed with an autosomal DNA test.

If MyHeritage identifies a connection between your family tree and another, you’ll be informed of the connection, so you can use that information to find out more and even discover new relatives. With 46 million family trees in its data banks, MyHeritage offers arguably the best DNA test to find siblings.

MyHeritage users who are uploading DNA data from a previous test can expect results in a couple of days, whereas those using one of MyHeritage’s sibling DNA kits will have to wait three to four weeks. Still, if it means you find a long-lost brother, it’s well worth the wait!

For more information read our MyHeritage review here.

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#2 23andMe

23andme logoFor some, it’s not about finding new siblings but establishing the relationship between themselves and those they grew up with. Although 23andMe will also suggest possible connections using a similar method as MyHeritage’s Smart Match, it also makes comparing your own DNA to a possible relative extremely straightforward.

Once you’ve found a possible match, you can share your own DNA profile with your siblings using 23andMe’s Your Connections page. Once there, you can click on your possible brother or sister’s name and compare your genomes side by side.

Reading the information is simple with 23andMe and users will be quick to note that they share some fully identical genetic features with full siblings, whereas with their half-siblings, they share only half-identical regions. Read our review here.

23andMe uses haplogroups to identify maternal and paternal connections and similarities. This means that you could discover distant cousins in exotic places as well as brothers and sisters closer to home. To get the process underway, all you have to do is order a sibling DNA kit, spit into the tube and then send it off to the lab. Around three to fives weeks later, you can log into your online account and find out just who you really are and who you’re related to.

23andMe is known for its accuracy, although men will receive a more complete idea of their parentage as they inherit testable genetic material from both parents, whereas women can only be tested for the haplogroups on their mother’s side. Fortunately, the main focus of the best DNA tests to find siblings is on autosomal DNA which passed from both parents to male and female descendants.

In addition to testing to see if you are related, you can use 23andMe to find out more about how your body operates on a genetic level, improving your life spiritually by extending your family and physically by boosting your health.

For more information read our 23andMe review here.

Learn More About Yourself, With 23andMe DNA Testing Kit

#3 AncestryDNA

ancestry logoUnlike 23andMe and other similar services, AncestryDNA doesn’t test either y-DNA or mtDNA, rather sticking to what it knows best – autosomal DNA testing. Autosomal DNA testing is something of a recent breakthrough and enables scientists and researchers to compare 22 pairs of autosomal chromosomes and accurately establish relationships between siblings and even cousins. Although the accuracy begins to decline the more distant the relationship, it’s still one of the best DNA tests to find siblings.

So, can a DNA test prove half-siblings? Yes, it can and AncestryDNA has adopted similar methods to those used by 23andMe in an effort to simplify the process. Nevertheless, even in close relationships, like brother and sister, there can be some overlapping.

For example, while AncestryDNA’s sibling DNA kits can distinguish between half and full siblings, there are individuals who share more than the average amount of DNA even though they’re only half-siblings. Nevertheless, AncestryDNA is confident that, by using fully identifiable regions, their tests are capable of accurately establishing whether two individuals share two parents or just one.

Although competitively priced, AncestryDNA isn’t quite as thorough or accurate as MyHeritage and 23andME, and the results also take longer – usually between six and eight weeks – so, isn’t the best option for those looking for a fast turnaround time. Nevertheless, AncestryDNA is a well-established, reputable DNA testing company that offers one of the best DNA tests for siblings and half-siblings, providing reports that are easy to understand even if the contents might be hard to swallow!

For more information read our AncestryDNA review here.

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#4 LivingDNA

Living DNA LogoIf the thought of spitting into a tube makes your stomach turn, then LivingDNA’s cheek swab test might be the perfect solution, but you’re going to have to be patient as results can take up to 12 weeks! On the plus side, the price is competitive and the results both accurate and easy to understand.

Unlike some home DNA testing companies, like 23andMe for example, LivingDNA has just one test available but this is more than sufficient to help you find family members or even ascertain whether your brother is a full sibling or just half a one (as you’ve always suspected!).

Earlier this year, LivingDNA launched its new DNA-driving matching system called Family Networks. This uses all three types of DNA to conduct a thorough analysis and take the guesswork out of your familial relationships. All you need to start searching is your DNA, gender and your date of birth.

Although LivingDNA’s Family Networks isn’t as fast as some, taking up to three weeks to identify your first matches, it is one of the most accurate around due to the fact that it analyses all three types of DNA in its matching process. As more people add their DNA, so the likelihood of finding a match increases so, even if nothing happens for a month two, that’s not to say there’s not some half sibling out there waiting to meet you!

In addition to your DNA results, LivingDNA gives users the option of adding a personalized ancestry book to their order. This is a hard copy of your results and an explanation of what it all means and how scientists have developed genetic testing over the years. If you’re on the lookout for new siblings and half-siblings, opting into LivingDNA’s Family Networks is a worthwhile move, even if you choose to get tested with a different company.

For more information read our Living DNA review here.

Try Living DNA Now

#5 Family Tree DNA

Family Tree DNA LogoTo be fair, with a name like Family Tree DNA, you’d expect this service to be at the top of the list, rather than the bottom. Unfortunately, although Family Tree DNA produces some excellent results, as it does three different tests for each of the three types of DNA, you could end up spending three times as much securing those results.

On the plus side, the entry-level test offered by Family Tree DNA is one of the best DNA tests to find siblings, giving users access to the Family Finder tool. This works in a similar way to LivingDNA’s Family Networks but also differentiates matches according to parental lines. If you suspect you have a half sibling on your father’s side, for example, you need only explore that tab, rather than exploring all the possible matches Family Tree DNA conjures up.

Another benefit of the Family Finder sibling DNA kits is that you’ll get your results within two to four weeks, making it ideal for those with a limited timeframe. Like LivingDNA, Family Tree DNA has opted for the cheek swab saliva collection format which is often more appealing than spitting into a tube.

In addition to getting access to the family matching tool, Family Tree DNA users will also receive detailed information about where their ancestors lived and who they were. Another useful feature is the chromosome browser which not only shows exactly which segments of your DNA match with your siblings or half-siblings, but also where on the chromosome the similarities begin and end.

A useful tool and effective way of finding out the truth about your family and ancestry, Family Tree DNA may not be as thorough as MyHeritage or 23andMe but is a great alternative for those who need results quickly.

You can find out more with our review here.

Try FamilyTreeDNA Now


Although the science behind even the best DNA test for siblings is still pretty new and evolving every day, services like MyHeritage and 23andMe can offer some interesting insights into who you are and who you’re related to. It’s nevertheless important to bear in mind that the sibling DNA kits available from these services are not suitable to be used as evidence in a paternity case, for example, and users should be cautious about drawing too many conclusions from their results.

Having said that, if you find a close match using a Family Network or DNA matching tool, chances are, you’ve found a long-lost member of your family. Given both the affordability and ease of use of the best DNA tests for half-siblings and siblings, if you have any doubts or unanswered questions about your family, it’s a worthwhile investment. Not only could it explain differences between you and your brother that have been nagging at you for years, but it could also introduce you to a whole new family!

Now we’ve whetted your appetite for all things DNA, why not find out more about these essential building blocks of life and how scientists are using new techniques to dig deeper into humanity’s past and present?

Finding relatives isn’t the only thing you can do with your DNA test results either, and there are a host of uses for this critical data, from changing your fitness regime to suit your genes to designing an entire vacation around your ancestral origins. If you’re keen to find out more about what you can do with your DNA data, then you should check this out.

As home DNA testing becomes increasingly popular and DNA testing companies like MyHeritage expand their DNA databases, so results and possible familial matches become more accurate. You’ve certainly got a lot to gain from the best DNA test to find siblings and very little to lose, except a bit of spit and a few dollars which, given how much having a sister in your life is worth, is the equivalent of nothing at all!