> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/web/get-started/samples/measurement-viewer.md).

# Measurement annotations

Calculate area & measure distance in PDFs with JavaScript. Convert & measure CAD files in the browser. Customize the scale of your measurement

This JavaScript sample lets you calculate area dimensions, measure between lines or trace perimeters in PDFs. The scale of measurement can be customized based on requirements and calculations are displayed as a comment annotation. This functionality is commonly used in construction software to measure the amount of material required during 'Take-off'. This sample works on all browsers (including IE11) and mobile devices without using plug-ins. To see an example visit [Measurement tools demo](https://showcase.apryse.com/measurement-tools/). Learn more about our [Web SDK](/web/get-started/guides.md).

{% tabs %}
{% tab title="JavaScript" %}
{% code lineNumbers="true" %}

```js
// eslint-disable-next-line no-undef
const WebViewerConstructor = isWebComponent() ? WebViewer.WebComponent : WebViewer;

WebViewerConstructor(
  {
    fullAPI: true, // Only required if using snapping feature
    path: '../../../lib',
    initialDoc: '../../../samples/files/houseplan-A.pdf',
    enableMeasurement: true,
  },
  document.getElementById('viewer')
).then(instance => {
  samplesSetup(instance);
  instance.UI.setToolbarGroup('toolbarGroup-Measure');

  // If you would like to have snapping features enabled, you could do so with the following:
  // const { documentViewer, Tools } = instance.Core;
  // const distanceMeasurementTool = documentViewer.getTool(Tools.ToolNames.DISTANCE_MEASUREMENT);
  // distanceMeasurementTool.setSnapMode(Tools.SnapModes.DEFAULT);

  // open notes panel by default
  instance.UI.openElements(['notesPanel']);

  document.getElementById('select').onchange = e => {
    instance.UI.loadDocument(e.target.value);
  };

  document.getElementById('file-picker').onchange = e => {
    const file = e.target.files[0];
    if (file) {
      instance.UI.loadDocument(file);
    }
  };

  document.getElementById('url-form').onsubmit = e => {
    e.preventDefault();
    instance.UI.loadDocument(document.getElementById('url').value);
  };
});
```

{% endcode %}
{% endtab %}
{% endtabs %}


---

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