FamilySearch Family Tree is the world’s largest collaborative public family tree, with about 1.74 billion names as of July 2025. Family Tree makes it easy to do your family history, with exciting features such as record hints, source linking, photo and story management, and artificial intelligence (AI) tools.
Adding your family members to the collaborative tree can be a thrilling experience. But running into duplicate family members? Not so much. In this article, you’ll learn where duplicates come from and why they’re a problem. You'll also learn best practices for merging duplicates.
Where Do Duplicates Come From, and Why Are They a Problem?
The ultimate goal for Family Tree is to build a pedigree of the human family with one accurate profile for each person, linked to other profiles by correct relationships. That raises a question. If each person is supposed to have only one profile, why are there sometimes duplicate profiles in Family Tree?
Some duplicate profiles were imported from older systems, such as new.FamilySearch.org. Today, though, FamilySearch has sophisticated duplicate checking, which is improving all the time. Duplicates are usually added when profiles are created with limited or incorrect information that makes it difficult to tell if a profile already exists for the same person.
Why are duplicates a problem in a collaborative tree? There are several reasons.
- Duplicates can cause confusion, especially for people learning to do family history or use Family Tree.
- They cause duplicate research.
- They may lead to incorrect merges, especially when profiles have limited or incorrect information.
- People have to spend time researching and merging duplicates instead of making progress on their family history.
In other words, duplicates get in the way of creating an accurate tree of humankind. That being said, in a shared tree, we will probably always need to merge duplicates. However, taking some care when adding profiles can help reduce duplication significantly, which reduces the need for merging.
The Balance Between Duplicates and Merges
While duplicates cause issues in the tree, incorrect merges—merges of profiles that don’t represent the same person—cause even more issues. On an incorrectly merged profile, information tends to be contradictory or incorrect. Since Family Tree generates hints from information on the profile page, subsequent hints may be wrong as well. Incorrect merges often snowball across families and generations as users rely on inaccurate information, often without realizing it.
Incorrect merges that take seconds to make often take hours to untangle. So it’s important to be confident that profiles really represent the same person before merging them.
How Do I Find Possible Duplicates?
There are several ways to identify duplicate profiles in Family Tree.
Possible Duplicate Hint on a Profile
When FamilySearch has identified a possible duplicate of a profile, a Possible Duplicate hint appears in the profile’s Research Help box. Only close matches are displayed. While you always need to verify these possible duplicates, chances are good that you’ll need to merge them.
Find Similar People
The Find Similar People option appears in the Tools section of the profile page. It is used to find profiles that are not close enough to the current profile to appear as possible duplicates but that are still close enough that they may be worth checking.
Find Function
If you have reason to believe a duplicate is in the tree that the system isn’t finding—for instance, you’ve been seeing a lot of hard-to-find duplicates on other family members—you can use the Find function to enter your own search parameters to look for similar profiles. For example, you can include the name of a spouse or parent you’ve found through research who doesn’t yet appear on the profile.
Possible Duplicate Children or Spouses
If you notice that a person has multiple spouses with the same name or children with the same name who were born the same year, you may want to look for possible duplicates. But be careful. A person could have married 2 spouses with the same first name or last name. In some cultures, parents might give a child the same name as a deceased older sibling.
Possible Matches When Adding a Profile
When you try to create a profile in Family Tree, the system looks for existing profiles similar to the one you’re trying to create and displays any close matches. Look at these matches carefully to avoid adding a duplicate profile.
Determining Whether Profiles Are Duplicates
The most important part of a merge takes place before you start the merge. Often, the information you need to determine whether 2 profiles should be merged isn’t visible on the merge screen.
You can increase your confidence that a merge is correct by doing the following:
- Determine the intended identity of the profile. When people create a profile, they intend it to represent a certain human being. We can call this the “intended identity.” The intended identity can usually be determined by looking at the earliest entries in the change log. It is the baseline for determining whether profiles represent the same person. Checking the intended identity before merging is important because if a profile has already been incorrectly merged, the apparent identity of the profile may have changed from the original identity.
- If a profile has been merged incorrectly, repair it before doing another merge. Merging a profile that has already been incorrectly merged makes the problem worse and increases the time and effort needed to repair it.
- Check attached sources, but don’t rely only on them to prove identity. Some attached sources may not apply to the profile. Compare them to the intended identity to be sure.
- Look for additional sources, and add missing information. For example, if a profile doesn’t have birth information, you may be able to find sources that provide it. Adding the birth information can help you determine if the merge is correct.
- Rely on evidence, not simply on a lack of conflicts. For instance, one profile might have birth information while the other doesn’t. While there isn’t an obvious conflict, without the missing birth information you can’t be sure whether the births are the same. And if the births turn out to be different, the profiles may represent different people.
Doing the Merge
Once you are confident that profiles really represent the same person, here’s how to merge.
Step 1: Begin the Merge
If the possible duplicate appears in the Research Help box on the profile page, select the duplicate, and then click Review Merge.
If the possible duplicate doesn’t appear in the Research Help box, click Merge by ID in the Tools box. Enter the person ID (PID) for the possible duplicate, and then click Continue.
Both of these options take you to the merge page.
Step 2: Review the Information on the Merge Page
The merge page shows the following information:
- The profile that will be deleted if you complete the merge.
- The profile that will survive (shown in its premerge state) if you complete the merge.
- The profile that will survive with any changes that will be made as part of the merge.
- A recommendation for whether or not to do the merge or a warning that the merge cannot be done.
(The numbers in the list above correspond to the numbers on the image below.)
By default, the profile you are on when you start the merge is the surviving profile. If you decide you would like the other profile to be the survivor, click the Switch button near the name on the duplicate profile.
Start by reviewing the recommendation at the top of the page. The table below describes 3 recommendations you may see, depending on the consistency between the 2 profiles. You may also see a warning that a merge cannot be done.
Consistency Evaluation | Message |
| No obvious problems | 
|
| Several inconsistencies need review | 
|
| Major inconsistencies | 
|
| Merge obviously wrong (includes explanation) | 
|
- One profile is for a living person, and the other is for a deceased person.
- The profiles are of people of different sexes.
- The profiles are for a parent and a child or for a person’s own spouse.
To see a full list of reasons, see “Why do merges fail in Family Tree?”
Keeping the recommendation in mind, compare the profiles. Ask yourself:
- How well does the information match? For instance, is the birth information on the profiles identical or close, or is it substantially different?
- Do any warnings indicate that more research is needed or that the profiles may not represent the same person?
- Is information missing that is needed to increase confidence that the merge is correct? For instance, if one profile has birth information and the other doesn’t, finding the missing information can help you be more confident that the merge is correct.
Keep in mind that in many areas of the world, particularly before the 1900s, it was common for people with the same or similar names to live in the same area and be born around the same time. Pay close attention to names, dates, and relationships that may not match exactly.
Step 3: Decide Whether to Merge, and Take the Appropriate Action
As you review the possible merge, you’ll come to one of 3 conclusions:
- The profiles clearly represent the same person and should be merged.
- The profiles don’t represent the same person and shouldn’t be merged.
- Inconsistencies or lack of information make it difficult or impossible to tell if the profiles should be merged.
What to Do in Each Case
If the Profiles Should Be Merged
- When information differs between profiles (for example, they have different death dates), an option button appears next to each item so you can select the one you want to keep. By default, the item on the surviving person is selected. Review each item, and change any default selections so that the resulting profile looks correct.
- Click Merge.
- In the Reason for Merge box, explain briefly how you know the profiles represent the same person. It’s a good idea to include the names and PIDs.
- Click Submit.
If the Profiles Should Not Be Merged
1. In the top right of the merge screen, click Not a Match.
2. In the pop-up box that appears, list one or more differences that show that the profiles aren’t for the same person.
3. Click Save.
If You're Not Sure the Profiles Should Be Merged
If you’re not sure that profiles should be merged, it’s better not to merge them. On the merge screen, click Cancel to back out of the merge. You may want to do more research, or let this one go and move on to other tasks.
What to Expect After a Merge
After finishing the merge, you’ll see a message on the screen telling you that the merge was successful. If you're having second thoughts, you can also click Undo Merge.
You may be wondering what happens to items that don’t appear on the merge screen, such as notes, memories, and ordinance information (for users who are members of The Church of Jesus Christ of Latter-day Saints). All these items are transferred to the surviving profile. Sometimes it takes a few moments for everything to transfer. If you don’t see items right away, try refreshing the page or just wait a few minutes.
What If I Discover a Merge Is Wrong?
Occasionally, even when you’re careful, you may realize that you’ve merged profiles that really represent different people. Or you may come across a profile that shows signs of an incorrect merge—for instance, you see very different sets of parents, or you see a christening that takes place before a birth. You can find guidance for repairing incorrect merges in “How to Fix Incorrect Merges in the Family Tree.”
Final Advice
Some profiles are obvious duplicates, but thought, care, and research are usually needed to determine if 2 profiles represent the same person. As you follow guidance in this article, you can perform merges with greater confidence. The time required to make sure a merge is correct is time well spent.
Related Articles
At FamilySearch, we care about connecting you with your family, and we provide fun discovery experiences and family history services for free. Why? Because we cherish families and believe that connecting generations can improve our lives now and forever. We are a nonprofit organization sponsored by The Church of Jesus Christ of Latter-day Saints. To learn more about our beliefs, click here.
