HTML 5 <canvas> Tag
The HTML <canvas> tag is used for creating graphics on the fly. It can be used for rendering graphs, game graphics, or other visual images.
To draw on the canvas, the <canvas> tag is used in conjunction with the getContext(contextId) method.
Any content between the <canvas></canvas> tags is "fallback content"- meaning, it will be displayed only if the canvas cannot be displayed.
The <canvas> tag was introduced in HTML 5.
Example
Modify the code below, then click "Update". See below for attributes.
Attributes
HTML tags can contain one or more attributes. Attributes are added to a tag to provide the browser with more information about how the tag should appear or behave. Attributes consist of a name and a value separated by an equals (=) sign, with the value surrounded by double quotes. Here's an example, style="color:black;".
There are 3 kinds of attributes that you can add to your HTML tags: Element-specific, global, and event handler content attributes.
The attributes that you can add to this tag are listed below.
Element-Specific Attributes
The following table shows the attributes that are specific to this tag/element.
| Attribute | Description |
|---|---|
| width | Specifies the canvas width in pixels. The default value is 300.
Possible values: [Non-negative integer] (for example, 300) |
| height | Specifies the canvas height in pixels. The default value is 150.
Possible values: [Non-negative integer] (for example, 150) |
Global Attributes
The following attributes are standard across all HTML 5 tags.
| accesskey | hidden | itemtype |
| class | id | lang |
| contenteditable | inert | spellcheck |
| contextmenu | itemid | style |
| dir | itemprop | tabindex |
| draggable | itemref | title |
| dropzone | itemscope | translate |
For a full explanation of these attributes, see HTML 5 global attributes.
Event Handler Content Attributes
Event handler content attributes enable you to invoke a script from within your HTML. The script is invoked when a certain "event" occurs. Each event handler content attribute deals with a different event.
Here are the standard HTML 5 event handler content attributes.
| onabort | onerror* | onmousewheel |
| onblur* | onfocus* | onpause |
| oncanplay | onformchange | onplay |
| oncanplaythrough | onforminput | onplaying |
| onchange | oninput | onprogress |
| onclick | oninvalid | onratechange |
| oncontextmenu | onkeydown | onreadystatechange |
| ondblclick | onkeypress | onscroll |
| ondrag | onkeyup | onseeked |
| ondragend | onload* | onseeking |
| ondragenter | onloadeddata | onselect |
| ondragleave | onloadedmetadata | onshow |
| ondragover | onloadstart | onstalled |
| ondragstart | onmousedown | onsubmit |
| ondrop | onmousemove | onsuspend |
| ondurationchange | onmouseout | ontimeupdate |
| onemptied | onmouseover | onvolumechange |
| onended | onmouseup | onwaiting |
For a full explanation of these attributes, see HTML 5 event handler content attributes.