Element: mousemove event

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨July 2015⁩.

Themousemove event is fired at an element when a pointing device (usually a mouse) is moved while the cursor's hotspot is inside it.

These events happen whether or not any mouse buttons are pressed. They can fire at a very high rate, depends on how fast the user moves the mouse, how fast the machine is, what other tasks and processes are happening, etc.

Syntax

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

addEventListener("mousemove", (event) => { })onmousemove = (event) => { }

Event type

AMouseEvent. Inherits fromUIEvent andEvent.

Event properties

This interface also inherits properties of its parents,UIEvent andEvent.

MouseEvent.altKeyRead only: Returnstrue if thealt key was down when the mouse event was fired.
MouseEvent.buttonRead only: The button number that was pressed (if applicable) when the mouse event was fired.
MouseEvent.buttonsRead only: The buttons being pressed (if any) when the mouse event was fired.
MouseEvent.clientXRead only: The X coordinate of the mouse pointer inviewport coordinates.
MouseEvent.clientYRead only: The Y coordinate of the mouse pointer inviewport coordinates.
MouseEvent.ctrlKeyRead only: Returnstrue if thecontrol key was down when the mouse event was fired.
MouseEvent.layerXNon-standardRead only: Returns the horizontal coordinate of the event relative to the current layer.
MouseEvent.layerYNon-standardRead only: Returns the vertical coordinate of the event relative to the current layer.
MouseEvent.metaKeyRead only: Returnstrue if themeta key was down when the mouse event was fired.
MouseEvent.movementXRead only: The X coordinate of the mouse pointer relative to the position of the lastmousemove event.
MouseEvent.movementYRead only: The Y coordinate of the mouse pointer relative to the position of the lastmousemove event.
MouseEvent.offsetXRead only: The X coordinate of the mouse pointer relative to the position of the padding edge of the target node.
MouseEvent.offsetYRead only: The Y coordinate of the mouse pointer relative to the position of the padding edge of the target node.
MouseEvent.pageXRead only: The X coordinate of the mouse pointer relative to the whole document.
MouseEvent.pageYRead only: The Y coordinate of the mouse pointer relative to the whole document.
MouseEvent.relatedTargetRead only: The secondary target for the event, if there is one.
MouseEvent.screenXRead only: The X coordinate of the mouse pointer inscreen coordinates.
MouseEvent.screenYRead only: The Y coordinate of the mouse pointer inscreen coordinates.
MouseEvent.shiftKeyRead only: Returnstrue if theshift key was down when the mouse event was fired.
MouseEvent.mozInputSourceNon-standardRead only: The type of device that generated the event (one of theMOZ_SOURCE_* constants).This lets you, for example, determine whether a mouse event was generated by an actual mouse or by a touch event (which might affect the degree of accuracy with which you interpret the coordinates associated with the event).
MouseEvent.webkitForceNon-standardRead only: The amount of pressure applied when clicking.
MouseEvent.xRead only: Alias forMouseEvent.clientX.
MouseEvent.yRead only: Alias forMouseEvent.clientY.

Examples

The following example uses themousedown,mousemove, andmouseup events to allow the user to draw on an HTMLcanvas. Its functionality is simple: the thickness of the line is set to 1, and the color is always black.

When the page loads, constantsmyPics andcontext are created to store a reference to the canvas and the 2d context we will use to draw.

Drawing begins when themousedown event fires. First we store the x and y coordinates of the mouse pointer in the variablesx andy, and then setisDrawing to true.

As the mouse moves over the page, themousemove event fires. IfisDrawing is true, the event handler calls thedrawLine function to draw a line from the storedx andy values to the current location.

When thedrawLine() function returns, we adjust the coordinates and then save them inx andy.

Themouseup event draws the final line segment, setsx andy to0, and stops further drawing by settingisDrawing tofalse.

HTML

html

<h1>Drawing with mouse events</h1><canvas width="560" height="360"></canvas>

CSS

css

canvas {  border: 1px solid black;  width: 560px;  height: 360px;}

JavaScript

// When true, moving the mouse draws on the canvaslet isDrawing = false;let x = 0;let y = 0;const myPics = document.getElementById("myPics");const context = myPics.getContext("2d");// event.offsetX, event.offsetY gives the (x,y) offset from the edge of the canvas.// Add the event listeners for mousedown, mousemove, and mouseupmyPics.addEventListener("mousedown", (e) => {  x = e.offsetX;  y = e.offsetY;  isDrawing = true;});myPics.addEventListener("mousemove", (e) => {  if (isDrawing) {    drawLine(context, x, y, e.offsetX, e.offsetY);    x = e.offsetX;    y = e.offsetY;  }});window.addEventListener("mouseup", (e) => {  if (isDrawing) {    drawLine(context, x, y, e.offsetX, e.offsetY);    x = 0;    y = 0;    isDrawing = false;  }});function drawLine(context, x1, y1, x2, y2) {  context.beginPath();  context.strokeStyle = "black";  context.lineWidth = 1;  context.moveTo(x1, y1);  context.lineTo(x2, y2);  context.stroke();  context.closePath();}