HTMLElement: dragstart event

{{APIRef("HTML Drag and Drop API")}}

The dragstart event is fired when the user starts dragging an element or text selection.

This event is cancelable and may bubble up to the {{domxref("Document")}} and {{domxref("Window")}} objects.

Syntax

Use the event name in methods like {{domxref("EventTarget.addEventListener", "addEventListener()")}}, or set an event handler property.

addEventListener("dragstart", (event) => { })

ondragstart = (event) => { }

Event type

A {{domxref("DragEvent")}}. Inherits from {{domxref("Event")}}.

{{InheritanceDiagram("DragEvent")}}

Event properties

In addition to the properties listed below, properties from the parent interface, {{domxref("Event")}}, are available.

• {{domxref('DragEvent.dataTransfer')}} {{ReadOnlyInline}}
  • : The data that is transferred during a drag-and-drop interaction.

Examples

Setting opacity on drag start

In this example, we have a draggable element inside a container. Try grabbing the element, dragging it, and then releasing it.

We listen for the dragstart event to make the element half transparent while dragged.

For a complete example of drag and drop, see the page for the drag event.

HTML

<div id="container">
  <div id="draggable" draggable="true">This div is draggable</div>
</div>
<div class="dropzone"></div>

CSS

body {
  /* Prevent the user from selecting text in the example */
  user-select: none;
}

#draggable {
  text-align: center;
  background: white;
}

#container {
  width: 200px;
  height: 20px;
  background: blueviolet;
  padding: 10px;
}

.dragging {
  opacity: 0.5;
}

JavaScript

const source = document.getElementById("draggable");
source.addEventListener("dragstart", (event) => {
  // make it half transparent
  event.target.classList.add("dragging");
});

source.addEventListener("dragend", (event) => {
  // reset the transparency
  event.target.classList.remove("dragging");
});

Result

{{EmbedLiveSample('Setting opacity on drag start')}}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• Other drag and drop events:
  • {{domxref("HTMLElement/drag_event", "drag")}}
  • {{domxref("HTMLElement/dragend_event", "dragend")}}
  • {{domxref("HTMLElement/dragover_event", "dragover")}}
  • {{domxref("HTMLElement/dragenter_event", "dragenter")}}
  • {{domxref("HTMLElement/dragleave_event", "dragleave")}}
  • {{domxref("HTMLElement/drop_event", "drop")}}