This is an improved Leeds Chart Generator Application. Please read the instructions, below the drawing canvas. Version date: Sept 10, 2025
This is an improved Leeds Chart Generator Application. Please read the instructions, below the drawing canvas. Version date: Sept 10, 2025
OVERVIEW
The Leeds Method was developed by Dana Leeds to cluster autosomal DNA matches into groups. Ideally, it produces four groups in which each group is related to one of your grandparents. Often, the results don't provide this ideal situation, but the Leeds method can still help you a lot in determining how your DNA matches are related to you.
The prior version of this application provided a way of quickly creating a Leeds Chart. However, because of the restrictions imposed by Google on Google Sites, it was not possible to copy the chart, save the chart, or reload the chart. This version provides a work-around to make copy, save, and load possible. There are now three tabs. Leeds Chart generation is performed on the Leeds Chart tab. When you click 'Copy Image', a png image of the complete drawing canvas is saved in the image tab. When you click 'Save', a JSON file is generated and placed into the File tab. This new version is in beta testing, so expect errors. Like all other apps on this website, they are provided 'as-is'. Feedback is greatly appreciated.
INSTRUCTIONS
Creating Your Leeds Chart
To use this application, please use a chromium-based browser such as Chrome, Edge, Brave, etc. Copy and paste works differently in Firefox, and so Firefox is not suitable to use with this application.
The first step in using this application is to capture your DNA match list from Ancestry.com. On your DNA match list page, scroll to the bottom and select whether you want to show 20 or 50 matches per page. A Leeds analysis typically uses your DNA matches in the range of 90-400cM, and you can use Ancestry's filters to show just the matches in this range. But, you can choose any range, or no filter, if you want.
On the Ancestry.com page listing DNA data, click CTRL-A then CTRL-C (CMD-A and CMD-C on a Mac) to copy the data to clipboard. In the Leeds Chart tab of this application, click the paste box below the "Leeds Chart Generator" title (above) to activate it, then click CTRL-V (or CMD-V) to paste the data into the paste box. You should get a 2-column table of the data. If you want to add more matches to this list, click 'yes' in the pop-up box; otherwise click 'no' and the app then switches to shared matches.
Note that with Ancestry.com's new data format, pressing CTRL-A does not always select all data on the page. It is recommended that you scroll to the end of the page and click blank space near the bottom of the page, then press CTRL-A. For the DNA match list, you will need to scroll to the bottom of the page to increase the listing amount from 20 to 50 matches per page.
In the Leeds method, the general rule is that you start with the highest cM match in the 90-400cM range. The app will highlight this match for you. You can capture the shared match data for this match, or another if you decide on a different starting point. Go to the shared match listing and again do CTRL-A and CTRL-C to capture data to the clipboard. Return to the app, and activate the paste box, then CTRL-v to paste the data into the paste box. You'll get your first column of matches.
The next shared match is the highest cM below 400cM that is unassigned in any group. Again, the app highlights it for your convenience. Capture the shared match data for this match as before, and add it to the app, as before. You'll get a 2nd column. Repeat, and you'll get 3rd and 4th columns.
The app should work whether your shared match data is the 'regular' type or the 'Pro' type.
You may wish to merge columns. Click the merge button, and select which column that you merge from and which you want to merge into, then press OK. In the standard Leeds method, there is just one color per column, but the app keeps color from both columns, as this may subsequently be helpful in analyzing the chart. If you make a mistake and want to delete a shared match column, there is a 'delete last column' button.
Click the title of a shared match column, and you will get a dialog box to change the title. As space is limited in the title box, keep it short!
There is copy button on the Leeds Chart tab. It is used to copy a png image of the Leeds Chart to the Images tab. Several images can be pasted into this tab sequentially. To capture an image, right-click on any part of the chart in the Images tab, then click "Copy Image". With the image in clipboard, then paste into your favorite image editor, or paste directly into Word, OneNote, etc., etc.
The algorithms in this application require data to be supplied in a specific format. So if Ancestry makes changes to their website, it is possible that that change will cause this application to stop working reliably. If it isn't working for you, it would be appreciated if you could send an email to colleyvillegenealogy@gmail.com with a brief description of what is going wrong.
Warning: Clicking the browser's refresh button will clear everything, so use 'refresh' only to start over.
Saving Your Leeds Chart Data
Click the save button and you will be taken to the File page. The text box will have have your Leeds Chart data in JSON format. Click 'Select All', then CTRL-c to copy the text to clipboard, and paste it into Notepad. Save that text file to your PC.
You can clear the text box using the 'Clear' button in the File tab.
Loading Your Leeds Chart
Open your saved JSON file in Notepad, click CTRL-a, then CTRL-c. This copies the GEDCOM file to clipboard. Paste it into the empty text box on the File tab. Then go to the Leeds Chart tab and click 'Load'
Final Remarks
To repeat, this app is in beta testing. It would be greatly appreciated if you would report bugs and suggest enhancements to: