HTML Drag and Drop API

HTML drag-and-drop uses the DOM event model and drag events inherited from mouse events. A typical drag operation begins when a user selects a draggable element, continues when the user drags the element to a droppable element, and then ends when the user releases the dragged element.

During drag operations, several event types are fired, and some events might fire many times, such as the drag and dragover events.

Each drag event type has an associated event handler:

This section is a summary of the basic steps to add drag-and-drop functionality to an application.

Identify what is draggable

Making an element draggable requires adding the draggable attribute and the dragstart event handler, as shown in the following code sample:

<script>
  function dragstartHandler(ev) {
    // Add the target element's id to the data transfer object
    ev.dataTransfer.setData("text/plain", ev.target.id);
  }

  window.addEventListener("DOMContentLoaded", () => {
    // Get the element by id
    const element = document.getElementById("p1");
    // Add the ondragstart event listener
    element.addEventListener("dragstart", dragstartHandler);
  });
</script>

<p id="p1" draggable="true">This element is draggable.</p>

For more information, see:

• Draggable attribute reference
• Drag operations guide

Define the drag's data

The application is free to include any number of data items in a drag operation. Each data item is a string of a particular type — typically a MIME type such as text/html.

Each drag event has a dataTransfer property that holds the event's data. This property (which is a DataTransfer object) also has methods to manage drag data. The setData() method is used to add an item to the drag data, as shown in the following example.

function dragstartHandler(ev) {
  // Add different types of drag data
  ev.dataTransfer.setData("text/plain", ev.target.innerText);
  ev.dataTransfer.setData("text/html", ev.target.outerHTML);
  ev.dataTransfer.setData(
    "text/uri-list",
    ev.target.ownerDocument.location.href,
  );
}

• For a list of common data types used in drag-and-drop (such as text, HTML, links, and files), see Recommended Drag Types.
• For more information about drag data, see Drag Data.

Define the drag image

By default, the browser supplies an image that appears beside the pointer during a drag operation. However, an application may define a custom image with the setDragImage() method, as shown in the following example.

// Create an image and then use it for the drag image.
// NOTE: change "example.gif" to a real image URL or the image
// will not be created and the default drag image will be used.
let img = new Image();
img.src = "example.gif";
function dragstartHandler(ev) {
  ev.dataTransfer.setDragImage(img, 10, 10);
}

Learn more about drag feedback images in:

• Setting the Drag Feedback Image

Define the drop effect

The dropEffect property is used to control the feedback the user is given during a drag-and-drop operation. It typically affects which cursor the browser displays while dragging. For example, when the user hovers over a drop target, the browser's cursor may indicate the type of operation that will occur.

Three effects may be defined:

1. copy indicates that the dragged data will be copied from its present location to the drop location.
2. move indicates that the dragged data will be moved from its present location to the drop location.
3. link indicates that some form of relationship or connection will be created between the source and drop locations.

During the drag operation, drag effects may be modified to indicate that certain effects are allowed at certain locations.

The following example shows how to use this property.

function dragstartHandler(ev) {
  ev.dataTransfer.dropEffect = "copy";
}

For more details, see:

• Drag Effects

Define a drop zone

By default, the browser prevents anything from happening when dropping something onto most HTML elements. To change that behavior so that an element becomes a drop zone or is droppable, the element must listen to both dragover and drop events.

The following example shows how to use those attributes, and includes basic event handlers for each attribute.

<script>
  function dragoverHandler(ev) {
    ev.preventDefault();
    ev.dataTransfer.dropEffect = "move";
  }
  function dropHandler(ev) {
    ev.preventDefault();
    // Get the id of the target and add the moved element to the target's DOM
    const data = ev.dataTransfer.getData("text/plain");
    ev.target.appendChild(document.getElementById(data));
  }
</script>

<p id="target" ondrop="dropHandler(event)" ondragover="dragoverHandler(event)">
  Drop Zone
</p>

Note that each handler calls preventDefault() to prevent additional event processing for this event (such as touch events or pointer events).

For more information, see:

• Specifying Drop Targets

Handle the drop effect

The handler for the drop event is free to process the drag data in an application-specific way.

Typically, an application uses the getData() method to retrieve drag items and then process them accordingly. Additionally, application semantics may differ depending on the value of the dropEffect and/or the state of modifier keys.

The following example shows a drop handler getting the source element's id from the drag data, and then using the id to move the source element to the drop element:

<script>
  function dragstartHandler(ev) {
    // Add the target element's id to the data transfer object
    ev.dataTransfer.setData("application/my-app", ev.target.id);
    ev.dataTransfer.effectAllowed = "move";
  }
  function dragoverHandler(ev) {
    ev.preventDefault();
    ev.dataTransfer.dropEffect = "move";
  }
  function dropHandler(ev) {
    ev.preventDefault();
    // Get the id of the target and add the moved element to the target's DOM
    const data = ev.dataTransfer.getData("application/my-app");
    ev.target.appendChild(document.getElementById(data));
  }
</script>

<p id="p1" draggable="true" ondragstart="dragstartHandler(event)">
  This element is draggable.
</p>
<div
  id="target"
  ondrop="dropHandler(event)"
  ondragover="dragoverHandler(event)">
  Drop Zone
</div>

For more information, see:

• Performing a Drop

Drag end

At the end of a drag operation, the dragend event fires at the source element — the element that was the target of the drag start.

This event fires regardless of whether the drag completed or was canceled. The dragend event handler can check the value of the dropEffect property to determine if the drag operation succeeded or not.

For more information about handling the end of a drag operation, see:

• Finishing a Drag

The HTML Drag and Drop interfaces are DragEvent, DataTransfer, DataTransferItem and DataTransferItemList.

The DragEvent interface has a constructor and one dataTransfer property, which is a DataTransfer object.

DataTransfer objects include the drag event's state, such as the type of drag being done (like copy or move), the drag's data (one or more items), and the MIME type of each drag item. DataTransfer objects also have methods to add or remove items to the drag's data.

The DragEvent and DataTransfer interfaces should be the only ones needed to add HTML Drag and Drop capabilities to an application.

Each DataTransfer object contains an items property, which is a list of DataTransferItem objects. A DataTransferItem object represents a single drag item, each with a kind property (either string or file) and a type property for the data item's MIME type. The DataTransferItem object also has methods to get the drag item's data.

The DataTransferItemList object is a list of DataTransferItem objects. The list object has methods to add a drag item to the list, remove a drag item from the list, and clear the list of all drag items.

A key difference between the DataTransfer and DataTransferItem interfaces is that the former uses the synchronous getData() method to access a drag item's data, but the latter instead uses the asynchronous getAsString() method.

• Copying and moving elements with the DataTransfer interface
• Copying and moving elements with the DataTransferListItem interface
• Dragging and dropping files (Firefox only): https://jsfiddle.net/9C2EF/
• Dragging and dropping files (All browsers): https://jsbin.com/hiqasek/
• A parking project using the Drag and Drop API: https://park.glitch.me/ (You can edit here)

• Drag Operations
• Recommended Drag Types
• HTML Living Standard: Drag and Drop
• Drag and Drop interoperability data from CanIUse