Are you looking for the best sibling test that will confirm whether you share one or two parents with someone?
You’ve come to the right place.
In this in-depth buying guide, we discuss sibling DNA tests, what they are for, and how they work. We also review the best sibling DNA tests you can buy online.
A sibling DNA test is different from an ancestry DNA test. You can use an ancestry test to confirm siblingship, but the test can also tell you a lot more about your family and ancestors.
If you are looking for an ancestry DNA test, read our 23andMe vs. AncestryDNA vs. Family Tree DNA comparison.
But if your aim is to find out whether someone is your full or half-sibling, then read on.
When you are not sure whether you share a parent or two with an individual.
In such a case, most DNA testing companies prefer comparing both your DNAs to that of the parent. This is especially helpful when you share a known parent.
Because you are more related to your parent than your sibling, it’s easier to establish siblingship by checking whether you have both inherited half your DNA from a certain parent.
But it’s not always that a parent is available for testing.
In that case, a sibling DNA test is the best option.
The test will tell you whether that person is a full sibling, half-sibling, or no relation at all.
You can also get a sibling DNA test for legal purposes, for instance, a paternity case.
A court-admissible DNA test is quite different from a normal test that you take just to know the truth.
The science is the same, but the process is more rigorous to ensure the reliability of the test. That’s why legal sibling DNA tests are usually more expensive.
|Sibling DNA Test||DNA Markers||Use in Court?||Price
|Family Tree DNA ||37||No||$
|23AndMe.com||700,000 unique markers||No||$
|AncestryDNA||700,000 unique markers||Yes||$$
The LiveWelltest is easy and fast.
They’ll send you two swab kits once you complete an order online. Once you both collect your samples, secure them, and mail them back in the prepaid envelope.
The samples are tested at an AABB, A2LA, and CAP certified lab.
LiveWell compares 23 genetic markers in each person to confirm their siblingship. Testing more markets increases accuracy and reduces the chances of inconclusive results.
They test three things:
From the time the lab receives your samples, your results will be ready in 3-5 days. You’ll receive them by email, but you can also request a hard copy at an extra fee.
Note that the report is not admissible in court. If you want a test you can use in legal proceedings, they sell one for $100 more than the normal sibling test.
If you are looking for a quick test, this is the best option. It is also the most flexible one, giving you plenty of options to suit your specific situation.
It works the same way as other online sibling DNA tests.
You order the test online and receive a swab kit in your mail. You take a cheek swab and send it to the lab for testing.
When ordering, you can instruct the lab to check whether you are full siblings vs. half-siblings or half-siblings vs. unrelated.
The company promises that results will be ready in one business day.
If you do not want to take a cheek swab or you want to test someone’s DNA without their knowledge, the company accepts alternative DNA samples such as fingernails, hairbrush, a toothbrush and so on.
The accuracy of the test using these samples depends on how much DNA they can collect.
Something else we love about BioGene’s versatility is that you can opt not to receive the kit in your mail. This is great if you have any privacy concerns.
They will guide you on how to make your own kit and provide you with a case number.
That’s not all.
While most companies will only accept samples from two individuals, BioGene gives you the option of including the sample of one mother for the same price. This increases the accuracy of the test.
Once the samples get to the lab, they test and compare 24 markers. That’s higher than most other sibling DNA tests. It increases accuracy.
What we like most about GenTrace is that they allow you to test up to seven siblings. So if you have a bunch of people whom you suspect are (or are not) your siblings, this is the best DNA test.
They have the basic 2-sibling test for $150. If you share a known mother, you can also have her tested for added accuracy. This will cost you $245 in total.
Beyond that, the price goes up slightly for every sibling you add.
They also sell court-admissible legal DNA tests starting at $255 for two siblings. As with the basic test, you can test up to 7 siblings.
Don’t worry if your siblings are in different cities or states. GenTrace lets you input multiple addresses for kit delivery. They can even deliver to different countries.
All kits are barcoded and will be tested together.
The results will be ready in 3-5 days after the lab receives all the sample kits. You’ll receive an email with a link to where you can download your report.
The report provides a siblingship index.
If the index is more than1.00, you are likely to be siblings. The higher the index is, the higher the likelihood that you are related.
If the index is less than 1.00, you are most likely not related.
There is also a separate index to indicate whether you are likely to be half or full siblings.
Like GenTrace, Genovate also offers the convenience of split shipping.
Just provide the two addresses the kits will be shipped to when checking out. The kits are given a matching barcode to make sure they are tested together.
Genovate is perfect for those who are looking for a budget sibling DNA test. They have on the cheapest siblingship tests.
On the downside, they test fewer markers than other companies. But their test is still reliable most of the time.
The report, which is ready in 1-3 business days after lab receipt, tells you whether you are siblings or not or whether you are half or full siblings.
Note that this is not a legal test. For a test that you can submit to a court or use in a legal proceeding, you’ll have to go physically to Genovate’s offices.
The legal test is also more expensive.
But if all you need to do is confirm whether someone is your sibling or not, Genovate is a great choice and an affordable one as well.
This is one of the most accurate and reliable sibling DNA tests. Unlike other companies that test 15-25 markets, My Forever DNA tests more than 40 markers.
Testing more markers significantly increases the accuracy of a DNA test.
The test is easy to take. Just order online, and you’ll receive the sampling kit in your mail. Take a cheek swab and send it to the lab.
The company allows split shipping, meaning you can have the kits delivered wherever your sibling is living.
After the lab receives the samples, test results take 2-3 business days.
The report will be sent to your email address. You can also have a physical copy sent to your mailing address though that will take longer.
The report tells you the likelihood of being full siblings, half-siblings, or no relation to someone.
While the results are very accurate most of the time, you still cannot use them in court.
But the company sells a legal sibling DNA test that is admissible in court or any legal matters.
Family Tree DNA or FTDNA is not explicitly a sibling DNA test. But it’s one of the best ways to determine if you are siblings with someone.
FTDNA helps people find DNA matches to whom they might be related.
So if you and your potential sibling take the FTDNA test, you can determine your siblingship by checking whether you are close DNA matches.
FTDNA sells several types of tests including Y-DNA, mtDNA, and Family Finder. That last one is the one you need.
Once you send in your sample, it will take 6-8 weeks before your results are out. It takes much longer than typical sibling DNA tests because of FTDNA tests for far more than just siblingship.
Your results will contain estimates of ethnic percentages, insights into your ancient ancestry and dozens or hundreds of matches that could be your relatives.
To determine whether someone is your sibling, check whether they show up on your matches list. If you are siblings, they should be high up on the list because they are close relatives.
You should also share between 2,000 and 2,500centiMorgans. If you are half-siblings, the figure can go as low as 1,800.
If you have both taken the test, have received your results but you don’t see them in your list of matches (and they don’t see you either), then it is likely that you are not related.
Perhaps you want to confirm whether you are siblings and at the same time find out whether there are any genetic health risks you both face.
23andMe provides a comprehensive health and ancestry test that can do both.
As with FTDNA, this is not a dedicated sibling DNA test. 23andMe will not send you a report telling you whether you are siblings with someone.
Rather, it’s up to you to check the list of DNA matches 23andMe spits out and see if your potential sibling appears.
You’ll also have to do a bit more sleuthing (checking cM count, looking up shared matches, chromosome painting, etc.)to determine whether they are full or half siblings.
That means that you both have to take the 23andMe test but separately. Once both your results are out, check which matches you have.
In addition to DNA matches, the 23andMe test also includes a health report. It tells you which diseases you are at risk of because of your genetics.
If you and your sibling are worried that a certain condition got passed down from one of your parents, this test can help you confirm it.
If you are doing a deep genealogical search that goes beyond your siblings, AncestryDNA is the best test.
We recommend it because they have the largest DNA database with over 10 million people. That means you are likely to find many more DNA matches than with any of the other tests.
As with 23andMe and FTDNA, you both have to take the test separately to find out if you are siblings.
If you appear in each other’s list of matches, you are related. AncestryDNA will provide more details to help you determine whether you are full or half siblings.
Your matches might also contain cousins and relatives you never knew you heard.
By studying these matches and looking up which other matches you share with them, you can find out a lot about your family.
If you want to go even further, pay for an Ancestry.com subscription.
This will give you access to billions of genealogical records that might help you trace some missing members of the family or make connections between different relatives.
For serious family researchers, AncestryDNA is a goldmine of information.
Here are the factors we consider most important when selecting the best sibling DNA tests.
Generally, the higher the number of markers tested, the more accurate the results will be.
Most companies test between 15 and 30 genetic markers. We consider anything below 20 to be too low for reliability.
Testing 20-30 markers or more ensures you don’t get any inconclusive results or false positives/negatives.
The credibility of the company itself matters a great deal as well.
We avoid picking tests with numerous complaints from customers regarding reliability and customer service.
Established and well-known tests like 23andMe, Genovate, and AncestryDNA are the best.
If you are getting a simple sibling DNA test, you shouldn’t have to wait for weeks to get results. The best tests take at most three business days to send the results.
Note that the turnaround period begins when the lab starts processing your sample. In total, it may take a week or two from when you ordered the test to get your results.
This is because of the extra time it takes for the company to send the sampling kit to you, for you to take a sample and send it back and for the lab to begin processing.
If you order from companies like 23andMe and FTDNA, the turnaround time is much longer; around 6-8 weeks.
But that’s because they test for many more things other than siblingship.
A good company should answer all your questions and help you understand your results.
We rate highly companies that provide excellent customer support through email and phone.
Your DNA information should remain confidential and secure. If a company says they retain the right to share or sell it with third parties, that’s a red flag.
We pick tests that provide a high level of privacy and confidentiality to customers.
The final major factor we consider when rating different tests is price.
Sibling DNA tests are typically more expensive than paternity tests. Most go for $200-$270. But there are also cheaper ones that cost less than $200.
We don’t automatically give the highest rating to the cheapest test. Rather, we compare price vs. value.
We prefer tests that give you a bigger bang for your buck. For instance, some tests allow you to also test a known shared mother, others provide split shipping, and others are more accurate (they test more markers) without being too expensive.
Most websites will ask you to specify which kind of test you want.
There are two types: full sibling and half-sibling DNA tests.
For any of these two types of tests, you can opt for basic peace of mind test or a more rigorous (and expensive) legal test.
Wondering whether you share both parents with someone? This is the best type of test.
A full sibling test determines if both of you have inherited roughly the same DNA from both your parents.
Since you each get 50% from your mother and father, you should share about 50% of your DNA.
By comparing your genetic markers, the test can determine if you are full siblings, half siblings, or completely unrelated.
If you want to confirm that you share at least one parent with someone, this is the best type of test.
By comparing your genetic markers, the lab will check whether you share roughly 25% of your DNA. If you do, that means you are half siblings.
The test can also confirm if there is no relation between the two of you.
Where possible, companies encourage test-takers also to have the known parent tested. This increases the accuracy of the test.
If you are involved in a court case where you need to prove you are siblings with someone, you can’t just get any sibling DNA test. It has to be a court-admissible test.
The science behind a basic test done for peace of mind and a legal test is the same. But with a legal test, there is a specific process that needs to be followed for the results to be admissible in court.
Specifically, the lab has to maintain a chain of custody.
A neutral third party has to confirm the identity of the persons taking the test, make sure the sampling kit and sample have not been tampered with and ensures the testing is done in a certified lab.
That’s why some companies will insist on in-office physical testing for legal tests.
But if you just need to know whether someone is your sibling, a basic at-home test will do.
Sibling DNA tests are tricky compared to paternity tests because siblings are more closely related to their parents than they are to each other.
That’s why many sibling DNA tests compare more locations or markers in the DNA to improve testing accuracy.
Whether you are getting a sibling test for peace of mind or a court case, here are a few tips for improving the accuracy and reliability of the results.
By comparing genetic markers between two supposed siblings.
If they share roughly 50% of their DNA, they are full siblings. If they share about 25% of their DNA, they are half-siblings. If they share very little of their DNA, they are not related (or might be cousins).
Paternity tests are generally more accurate because it is much easier to compare a child to their parent.
The accuracy of a sibling DNA test will depend on how many locations the lab compares. The minimum is usually 15 or 16. The ideal range is 20-30.
For extra accuracy, look for a company that tests at least 40 markers.
But no matter how many markers a lab tests, no DNA test is 100% accurate. In fact, your sibling DNA result will be a probability.
In most cases, a high probability is almost a guarantee that they are your sibling. But there is always a small chance that they might not.
Yes, it’s possible.
While each sibling gets roughly 50% of their DNA from each parent, the share from each parent is not exactly the same.
The parents themselves have a mixture of different genes passed down from earlier generations.
Because of a process called gene recombination (a shuffling of genes during fertilization of the egg), your mother can pass on different genes to you from those she passes on to your sibling.
The same with the father, resulting in slightly different DNA in siblings.
In fact, full siblings share only about 50% of their DNA because of the recombination process.
The more multi-racial your parents are, the more the genes get mixed up.
If you take an ancestry test from 23andMe, FTDNA or AncestryDNA, you might find that your ethnicity make up is also different from that of your sibling.
Even identical siblings, who theoretically share 100% of their DNA, have different DNA because of changes in how their individual genes express themselves.
That’s the complexity of DNA.
Yes, that’s always a possibility though it is rare.
It can happen if the lab tested too few markers and got a false positive/negative or the sample was not good enough.
If you have doubts about your results, test with another lab.
Yes, it can. The lab will check both your genetic markers to see if you share roughly 25% of your DNA.
If you do, then you are likely half-siblings. If it’s more, around 50%, you are full siblings.
Identical siblings share roughly 100% of DNA.
You inherit roughly the same amount of DNA from each parent. But it’s not always a clean 50/50 split.
Sometimes you can have slightly more DNA from one parent than the other.
Not necessarily. It will depend on the alleles inherited from the parents.
Only in a few cases is it a guarantee that both siblings will have the same blood type. E.g., When both parents have an O blood type.
But in many cases, blood type is by chance. It depends on which allele you get from each parent.
You can happen to have the same blood type as your sibling, or it can be different.