HTMLElement: dragstart event

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 Document and Window objects.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

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

ondragstart = (event) => {};

Event type

A DragEvent. Inherits from Event.

Event properties

In addition to the properties listed below, properties from the parent interface, Event, are available.

DragEvent.dataTransfer Read only: 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

html

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

CSS

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

Specifications

Specification
HTML Standard # ix-handler-ondragstart
HTML Standard # event-dnd-dragstart

Browser compatibility

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