Abstract: In order to improve performance and responsiveness for drag-and-drop actions for Web applications, the amount of JavaScript loaded and executed at each increment of the mouse as it moves during a drag-and-drop action should be minimized. This can be achieved by harnessing the efficient and native-code algorithms built into Web browsers. Instead of using a JavaScript algorithm to compute which drop target the mouse is on, an overlay with placeholders can be placed on top of the page using z-index, where the placeholders are placed directly on top of the drop targets. The current drop target can be computed using the browser's built-in onmouseover and onmouseout events on the placeholder elements, thus freeing the browser from loading and executing too much JavaScript.