--- title: HTMLCanvasElement slug: Web/API/HTMLCanvasElement tags: - API - Canvas - HTML DOM - Interface - NeedsTranslation - Reference - TopicStub translation_of: Web/API/HTMLCanvasElement ---
{{APIRef("Canvas API")}}

The HTMLCanvasElement interface provides properties and methods for manipulating the layout and presentation of canvas elements. The HTMLCanvasElement interface also inherits the properties and methods of the {{domxref("HTMLElement")}} interface.

{{InheritanceDiagram(600, 120)}}

Properties

Inherits properties from its parent, {{domxref("HTMLElement")}}.

{{domxref("HTMLCanvasElement.height")}}
Is a positive integer reflecting the {{htmlattrxref("height", "canvas")}} 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 150 is used.
{{domxref("HTMLCanvasElement.mozOpaque")}} {{non-standard_inline}}
Is a {{jsxref("Boolean")}} reflecting the {{htmlattrxref("moz-opaque", "canvas")}} HTML attribute of the {{HTMLElement("canvas")}} element. It lets the canvas know whether or not translucency will be a factor. If the canvas knows there's no translucency, painting performance can be optimized.
{{domxref("HTMLCanvasElement.width")}}
Is a positive integer reflecting the {{htmlattrxref("width", "canvas")}} 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.
{{domxref("HTMLCanvasElement.mozPrintCallback")}}{{non-standard_inline}}
Is a function that is Initially null, Web content can set this to a JavaScript function that will be called if the page is printed. This function can then redraw the canvas at a higher resolution that is suitable for the printer being used. See this blog post.

Methods

Inherits methods from its parent, {{domxref("HTMLElement")}}.

{{domxref("HTMLCanvasElement.captureStream()")}} {{experimental_inline}}
Returns a {{domxref("CanvasCaptureMediaStream")}} that is a real-time video capture of the surface of the canvas.
{{domxref("HTMLCanvasElement.getContext()")}}
Returns a drawing context on the canvas, or null if the context ID is not supported. A drawing context lets you draw on the canvas. Calling getContext with "2d" returns a {{domxref("CanvasRenderingContext2D")}} object, whereas calling it with "experimental-webgl" (or "webgl") returns a {{domxref("WebGLRenderingContext")}} object. This context is only available on browsers that implement WebGL.
{{domxref("HTMLCanvasElement.toDataURL()")}}
Returns a data-URL containing a representation of the image in the format specified by the type parameter (defaults to png). The returned image is in a resolution of 96dpi.
{{domxref("HTMLCanvasElement.toBlob()")}}
Creates a {{domxref("Blob")}} object representing the image contained in the canvas; this file may be cached on the disk or stored in memory at the discretion of the user agent.
{{domxref("HTMLCanvasElement.transferControlToOffscreen()")}} {{experimental_inline}}
Transfers control to an {{domxref("OffscreenCanvas")}} object, either on the main thread or on a worker.
{{domxref("HTMLCanvasElement.mozGetAsFile()")}} {{non-standard_inline}} {{deprecated_inline}}
Returns a {{domxref("File")}} object representing the image contained in the canvas; this file is a memory-based file, with the specified name. If type is not specified, the image type is image/png.

Specifications

Specification Status Comment
{{SpecName('Media Capture DOM Elements', '#html-media-element-media-capture-extensions', 'HTMLCanvasElement')}} {{Spec2('Media Capture DOM Elements')}} Adds the method captureStream().
{{SpecName('HTML WHATWG', "#the-canvas-element", "HTMLCanvasElement")}} {{Spec2('HTML WHATWG')}} The method getContext() now returns a {{domxref("RenderingContext")}} rather than an opaque object.
The methods probablySupportsContext(), setContext() and transferControlToProxy()have been added.
{{SpecName('HTML5.1', "scripting-1.html#the-canvas-element", "HTMLCanvasElement")}} {{Spec2('HTML5.1')}}  
{{SpecName('HTML5 W3C', "scripting-1.html#the-canvas-element", "HTMLCanvasElement")}} {{Spec2('HTML5 W3C')}} Initial definition.

Browser compatibility

{{CompatibilityTable}}
Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support (2D context) 4.0 {{CompatVersionUnknown}} {{CompatGeckoDesktop('1.9.2')}} 9.0 9.0 [1] 3.1
toBlob() 50 {{CompatNo}} {{CompatGeckoDesktop('19')}} [2] {{CompatUnknown}} {{CompatUnknown}} {{CompatNo}} (bug 71270)
probablySupportsContext(),
setContext(),
transferControlToProxy() {{obsolete_inline}}
{{CompatNo}} {{CompatUnknown}} {{CompatNo}} {{CompatNo}} {{CompatNo}} {{CompatNo}}
mozGetAsFile() {{non-standard_inline}} {{deprecated_inline}} {{CompatNo}} {{CompatNo}} {{CompatGeckoDesktop('2')}} {{CompatNo}} {{CompatNo}} {{CompatNo}}
captureStream() {{experimental_inline}} {{CompatNo}} {{CompatNo}} {{CompatGeckoDesktop('41')}} {{CompatNo}} {{CompatNo}} {{CompatNo}}
transferControlToOffscreen() {{experimental_inline}} {{CompatNo}} {{CompatNo}} {{CompatGeckoDesktop(44)}} [3] {{CompatNo}} {{CompatNo}} {{CompatNo}}
Feature Android Chrome for Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (2D context) 2.1 {{CompatVersionUnknown}} {{CompatVersionUnknown}} {{CompatVersionUnknown}} {{CompatUnknown}} 10.0 [1] 3.2
webgl context {{CompatUnknown}} {{CompatUnknown}} {{CompatUnknown}} {{CompatVersionUnknown}} as experimental-webgl {{CompatUnknown}} {{CompatUnknown}} {{CompatUnknown}}
toBlob() {{CompatNo}} (bug 67587) 50 {{CompatNo}} {{CompatGeckoMobile('18')}} [2] {{CompatUnknown}} {{CompatUnknown}} {{CompatNo}} (bug 71270)
probablySupportsContext(),
setContext(),
transferControlToProxy() {{obsolete_inline}}
{{CompatNo}} {{CompatNo}} {{CompatNo}} {{CompatNo}} {{CompatNo}} {{CompatNo}} {{CompatNo}}
mozGetAsFile() {{non-standard_inline}} {{deprecated_inline}} {{CompatNo}} {{CompatNo}} {{CompatNo}} {{CompatGeckoMobile('2')}} {{CompatNo}} {{CompatNo}} {{CompatNo}}
captureStream() {{experimental_inline}} {{CompatNo}} {{CompatNo}} {{CompatNo}} {{CompatGeckoMobile('41')}} {{CompatNo}} {{CompatNo}} {{CompatNo}}
transferControlToOffscreen() {{experimental_inline}} {{CompatNo}} {{CompatNo}} {{CompatNo}} {{CompatGeckoMobile(44)}} [3] {{CompatNo}} {{CompatNo}} {{CompatNo}}

[1] Opera Mini 5.0 and later has partial support.

[2] Support for the third parameter, has been added in Gecko 25 only: when used with the "image/jpeg" type, this argument specifies the image quality.

[3] This feature is behind a feature preference setting. In about:config, set gfx.offscreencanvas.enabled to true.

See also