Merging Two Persons

Merging Two Persons 150 150 Heredis Help Knowledgebase

While entering data in Heredis, you realize you have created a person who may already exist in your genealogy. Or you have imported your cousin’s genealogical data into yours and now find yourself with a bunch of duplicates…

Starting with Heredis 2022 , a brand-new merge module is now at your disposal! It will assist you from A to Z during this usually tricky process.

To locate a duplicate, you may:

  • Start a search for duplicates – read the article on (Windows) Search for duplicates in the file or (Mac) Search for duplicates in the file. Select two potential duplicates then click on Prepare merger.
  • Try to find potential duplicates in the persons’ panel. Once you have spotted a pair, choose one of them as the primary person and click on the drop-down menu Person > Merge with another person. Select the second person by clicking on the magnifying glass button (you will then access the list of existing persons to choose from).

Take a look at the summaries and comparison trees to make sure they are indeed duplicates. Should the person’s parents be duplicates, start merging them first.
Once you have reviewed the summaries and comparison trees, click on (Mac) Compare the 2 persons, (Windows) Prepare Merger to prepare the merger.

(Mac) Merging Persons popup window from the Person menu

(Windows) Merging Persons popup window from the Person menu

See also (Mac) Permanent control for duplicates or (Windows) Permanent control for duplicates for all details on search for duplicate feature.

Heredis will open a window to prepare your merger. This window contains several columns, colored bullets, arrow buttons, and switches. Let’s take a closer look at how to use them.

Note: a duplicate merger is irreversible; once you have validated and saved the changes to your file, you can no longer cancel it. Remember to back up your file before merging persons.

Columns and lines

The first column shows the names of the data categories and fields.
The “person” column on the left-hand side shows the first duplicate; the person’s name, and his/her potential Ahnentafel number can be found in the column heading.
The “person” column in the middle shows the data of the person who will result from the merger; this column is entitled “Merged person”.
The “person” column on the right-hand side shows the second duplicate; the person’s name, and his/her potential Ahnentafel number can be found in the column heading.

To save some screen space, data is organized into categories (or “sections”). These categories are folded; by clicking on the arrow preceding the category title, you can unfold it and view all the information available. The arrow will then point downwards; by clicking on it, you will be able to fold the section again.


Heredis has prepped up the work for. The data with a green background (in the middle column) has been pre-selected by Heredis. If there is no doubt that the data is identical for both duplicates, then Heredis will show the result in the middle column, colored in green.
However, we advise you take the time to doublecheck this data, just in case.

If there is any conflict, Heredis displays the line in the middle column in pink. It’s up to you to choose which data to keep and to resolve all conflicts before you validate the merger.

If the line is grayed out, it means that the data has been ignored. Heredis will not ignore data systematically, it is up to you to click on the switch to ignore a set of data. We will go back to this later.


A system of colored bullets, located at the end of the line for each item, shows you which items have conflicts and which do not, i.e., data that might be questionable for the merger.
The pink bullet indicates that there is at least one conflict. The green bullet means that Heredis has not encountered any potential issue.
A gray bullet shows that the dataset has been ignored.

At the bottom of the screen, you can visualize the progress of the conflict resolution. When it reaches 100%, the merger can be validated.

Uncomplete progress bar

Complete progress bar

To resolve conflicts more rapidly, we have created a “Next Conflict” button (lower-right corner of the window) that allows you to move from one conflict to the next without checking the data already in green. Click on it to move from one conflict to the next if you don’t want to check the remaining data.

The list of information to be checked may be shorter or longer depending on the amount of data entered. Everything is detailed, nothing has been put aside. Therefore, you should take your time.

Arrows and crosses

To select the data you wish to save from one of the two duplicates, click on the or arrow located next to the Merged person column.

Some fields could be concatenated. Hence, if you want to retain data from both duplicates for Occupation, Given Names, Notes, etc., you can do so by clicking on the left arrow and then on the right one (or from right to left, it works too).

On the other hand, some fields do not allow you to cumulate data from both sides. For example, you need to be either a Natural or a Legitimate child, you can sign or you cannot. Such fields cannot be combined. Similarly, the same rule applies to Flags: Confidential, Marked, Secondary…

If you made a mistake when selecting the 2 pieces of information, click on the cross to remove the information. Both will be removed, then you will only need to click on one of the 2 arrows to select the data you wish to keep. You can also choose not to keep any data at all. In this case, the central rectangle will read [data ignored].


Switches allow you to ignore an entire set of data versus individual pieces of data, as described above (using the cross). For example, if the merger allows me to gather all the information I need on a person, my Person Notes will no longer be of any use to me. By clicking the switch in the Person Note section, I intend to ignore my research notes and therefore will no longer have this information available in the merged person.

Switch icon is “on” so as to retain all data from this section

Switch icon is “off” so as to ignore all data from this section


Heredis places events of the same type side by side for the 2 persons to be merged. For example, both persons have a Birth event. Heredis puts on each side the 2 Birth events, even if they differ. It’s then up to you to solve the conflict. To do so, scroll down to the Person Events section, then to the Birth event line. Colored in pink, it will let you identify the issue right away. As an example, the capture below shows 2 different dates of birth.

You may only choose 1 of the 2 dates as it is not possible to cumulate both of them. If you need to investigate some more before validating the date for good, you still have the option to save the 2 events. Click on the white rectangle, i.e. Birth: September 8, 1896 – Harwich (Barnstable County), and choose None. A second Birth event line appears so the 2 events are no longer on the same line. After validation of the merger, the merged person will own 2 birth events. You will later need to manually remove the incorrect birth event from the list of events in the Personal Data entry screen.

Despite the various suggestions made by Heredis, you remain in full control and can choose what you wish to keep or not.

As for Families (spouses), Parents, and Children, the same principle applies. You can choose to keep one or the other or simply both by selecting None. Remember to unfold each section to doublecheck the data.

If the person has a child but no spouse (e.g. a child with an unknown father), an “Unnamed Spouse” line will appear so the child can be displayed.

In short:

  • Colored bullets indicate whether conflicts are present or not. Green means everything seems consistent, pink means you must doublecheck your data, grey means the data has been ignored.
  • Switches allow you to ignore a set of data, a section, or an entire event (date, place, status…). The section’s bullet point is grey if you chose to ignore this data.
  • Dropdown lists under Person Events allow you to select the event you wish to compare between both persons.
  • The cross allows you to ignore one single piece of information.
  • The Next Conflict button lets you move forward at a faster pace when resolving conflicts, without dwelling on what was predefined by Heredis.

When everything is set up properly and the progress bar shows 100%, the MERGE button becomes clickable at the bottom right of the screen. You can then click on it to validate the merger.