CanvasRenderingContext2D.rotate()

The CanvasRenderingContext2D.rotate() method of the Canvas 2D API adds a rotation to the transformation matrix. The angle argument represents a clockwise rotation angle and is expressed in radians.

Syntax

void ctx.rotate(angle);

Parameters

angle
The angle to rotate clockwise in radians. You can use degree * Math.PI / 180 if you want to calculate from a degree value.

The rotation center point is always the canvas origin. To change the center point, we will need to move the canvas by using the translate() method.

Examples

Using the rotate method

This is just a simple code snippet which uses the rotate method.

HTML

<canvas id="canvas"></canvas>

JavaScript

var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");

ctx.rotate(45 * Math.PI / 180);
ctx.fillRect(70,0,100,30);

// reset current transformation matrix to the identity matrix
ctx.setTransform(1, 0, 0, 1, 0, 0);

Edit the code below and see your changes update live in the canvas:

Playable code
<canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas>
<div class="playable-buttons">
  <input id="edit" type="button" value="Edit" />
  <input id="reset" type="button" value="Reset" />
</div>
<textarea id="code" class="playable-code">
ctx.rotate(45 * Math.PI / 180);
ctx.fillRect(70,0,100,30);
ctx.setTransform(1, 0, 0, 1, 0, 0);</textarea>
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var textarea = document.getElementById("code");
var reset = document.getElementById("reset");
var edit = document.getElementById("edit");
var code = textarea.value;

function drawCanvas() {
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  eval(textarea.value);
}

reset.addEventListener("click", function() {
  textarea.value = code;
  drawCanvas();
});

edit.addEventListener("click", function() {
  textarea.focus();
})

textarea.addEventListener("input", drawCanvas);
window.addEventListener("load", drawCanvas);

Specifications

Specification Status Comment
WHATWG HTML Living Standard
The definition of 'CanvasRenderingContext2D.rotate' in that specification.
Living Standard  

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)
Feature Android Chrome for Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

See also

Document Tags and Contributors

 Contributors to this page: erikadoyle, fscholz
 Last updated by: erikadoyle,