HTMLCanvasElement: width property

{{APIRef("Canvas API")}}

The HTMLCanvasElement.width property is a positive integer reflecting the width HTML attribute of the {{HTMLElement("canvas")}} element interpreted in CSS pixels. When the attribute is not specified, or if it is set to an invalid value, like a negative, the default value of 300 is used.

Setting the width property resets the entire rendering context to its default state. This includes clearing the canvas (backing buffer), resetting the current path, and resetting all properties like fillStyle and globalCompositeOperation. This reset occurs for all context types, and occurs even when setting width to its current value. To restore the previous content after changing the width, use {{domxref("CanvasRenderingContext2D.getImageData()")}} and {{domxref("CanvasRenderingContext2D.putImageData()")}}. Context properties must be separately tracked and restored.

This is one of the two properties, the other being {{domxref("HTMLCanvasElement.height")}}, that controls the size of the canvas.

Value

A number.

Examples

Given this {{HTMLElement("canvas")}} element:

<canvas id="canvas" width="300" height="300"></canvas>

You can get the width of the canvas with the following code:

const canvas = document.getElementById("canvas");
console.log(canvas.width); // 300

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("HTMLCanvasElement")}}: Interface used to define the HTMLCanvasElement.width property
• {{domxref("HTMLCanvasElement.height")}}: Other property used to control the size of the canvas
• {{domxref("HTMLEmbedElement.width")}}
• {{domxref("HTMLIFrameElement.width")}}
• {{domxref("HTMLImageElement.width")}}
• {{domxref("HTMLObjectElement.width")}}
• {{domxref("HTMLSourceElement.width")}}
• {{domxref("HTMLVideoElement.width")}}