HTML5 Canvas
The HTML <canvas>
element is used to draw graphics on a web page.
The graphic to the left is created with <canvas>
. It shows four
elements: a red rectangle, a gradient rectangle,
a multicolor rectangle, and a multicolor text.
What is HTML Canvas?
The HTML <canvas>
element is used to draw graphics, on the fly, via JavaScript.
The <canvas>
element is only a container for graphics. You must use
JavaScript to actually draw the graphics.
Canvas has several methods for drawing paths, boxes, circles, text, and adding images.
Browser Support
The numbers in the table specify the first browser version that fully supports the
<canvas>
element.
Element | |||||
---|---|---|---|---|---|
<canvas> | 4.0 | 9.0 | 2.0 | 3.1 | 9.0 |
Canvas Examples
A canvas is a rectangular area on an HTML page. By default, a canvas has no border and no content.
The markup looks like this:
<canvas id="myCanvas" width="200" height="100"></canvas>
Note: Always specify an id
attribute (to be referred to in a script),
and a width
and height
attribute to define the size of the canvas. To add a border, use the style
attribute.
Here is an example of a basic, empty canvas:
Example
<canvas id="myCanvas" width="200" height="100"
style="border:1px solid
#000000;">
</canvas>
Try it Yourself »
Draw a Line
Example
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.moveTo(0, 0);
ctx.lineTo(200, 100);
ctx.stroke();
Try it Yourself »
Draw a Circle
Example
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.beginPath();
ctx.arc(95, 50, 40, 0, 2 * Math.PI);
ctx.stroke();
Try it Yourself »
Draw a Text
Example
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.font = "30px Arial";
ctx.fillText("Hello World", 10, 50);
Try it Yourself »
Stroke Text
Example
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.font = "30px Arial";
ctx.strokeText("Hello World", 10, 50);
Try it Yourself »
Draw Linear Gradient
Example
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
// Create gradient
var grd = ctx.createLinearGradient(0, 0, 200, 0);
grd.addColorStop(0, "red");
grd.addColorStop(1, "white");
// Fill with gradient
ctx.fillStyle = grd;
ctx.fillRect(10, 10, 150, 80);
Try it Yourself »
Draw Circular Gradient
Example
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
// Create gradient
var grd = ctx.createRadialGradient(75, 50, 5, 90, 60, 100);
grd.addColorStop(0, "red");
grd.addColorStop(1, "white");
// Fill with gradient
ctx.fillStyle = grd;
ctx.fillRect(10, 10, 150, 80);
Try it Yourself »
Draw Image
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
var img = document.getElementById("scream");
ctx.drawImage(img, 10, 10);
Try it Yourself »
HTML Canvas Tutorial
To learn all about HTML <canvas>
, Visit our complete HTML Canvas Tutorial.