Dendrogram Cluster Mapping Visual: Draw Hierarchical Branching, Free & Online

Use this free dendrogram cluster mapping visual in your browser. No sign-up, no download and no upload: everything runs on your own device, so your data stays private.

What this tool does

A dendrogram shows how items cluster step by step: close items join low, distant groups join high. This tool draws one from a leaf list plus merge lines, so you can sketch the output of a clustering run for a slide or a report without rerunning the analysis. Merge heights are drawn to scale, so the vertical gaps carry real meaning.

How to use it

Paste or type your leaf list and merge steps in the box above.
Adjust any settings, such as cutoffs, scales or styles, to match your data.
Click the run button and read the output below the tool.
Check the summary numbers before you copy anything into a document.
Copy the output, code or image into your figure, slide or report.

Worked example

Use leaves A, B, C, D with merges A+B at 1, AB+C at 2 and ABC+D at 4. The tree joins A and B low, adds C higher, and D last at the top, which reads as D being the most distant item. That is the whole clustering story in one picture.

Tips for better results

List merges in increasing height order, or the branches will cross.

Honest limits

The tool draws the merges you type; it does not compute clusters from data or choose a linkage method. Your merge heights must come from your own analysis.

Choosing the right settings

Start with the default values. They are chosen to show a sensible result at once, so you can see the layout before you touch your own data. Then change one setting at a time. Changing one thing at a time is the fastest way to learn what each control does, and it stops two changes from cancelling each other out. If the output looks wrong, check the input format first: a missing comma, a swapped column or a stray space causes most errors, and the tool reports what it received in its summary line.

Using the result in a figure

For a figure, keep the output simple. One message per figure, short labels, and a caption that states the method and the settings you used will serve readers better than a dense, decorated chart. If a journal or supervisor will see the result, note the tool name, the input values and any cutoff in your methods or caption, so the figure can be reproduced later. That habit also helps you: six months from now, the caption is the only record of how the figure was made.

Common questions

Do I need an account? No. The dendrogram cluster mapping visual runs entirely in your browser with no sign-up and no saved data.

Is my data uploaded anywhere? No. Your leaf list and merge steps stays on your device, which is why the tool is safe for unpublished work.

Can I use the output in a paper or presentation? Yes. The output is yours to reuse; just check it visually once, note the settings in your caption, and credit the method, not the tool, in your references.

What if the result looks wrong? Check the input format first, then change one setting at a time. Most errors come from a missing comma, a swapped column, or a value outside the expected range, and the summary line under the tool shows what it actually received.

Try the dendrogram cluster mapping visual above with the sample data, then with your own. It is free, it needs no account, and it works in any modern browser.

When you reuse the result, keep a short record of the inputs and settings you used. A one-line note in your project file, such as the data pasted, the cutoff chosen and the date, is enough to reproduce the figure later. If a collaborator questions a number, that note lets you rebuild the exact output in seconds instead of guessing what changed.

Embed this tool on your website — free

Copy the code below to add this working tool to your own page. A small credit link stays with it — that’s all we ask.