CanvasRenderingContext2D: createRadialGradient() method

The CanvasRenderingContext2D.createRadialGradient() method of the Canvas 2D API creates a radial gradient using the size and coordinates of two circles.

This method returns a CanvasGradient. To be applied to a shape, the gradient must first be assigned to the fillStyle or strokeStyle properties.

Syntax

createRadialGradient(x0, y0, r0, x1, y1, r1)

The createRadialGradient() method is specified by six parameters, three defining the gradient's start circle, and three defining the end circle.

Parameters

x0

The x-axis coordinate of the start circle.

y0

The y-axis coordinate of the start circle.

r0

The radius of the start circle. Must be non-negative and finite.

x1

The x-axis coordinate of the end circle.

y1

The y-axis coordinate of the end circle.

r1

The radius of the end circle. Must be non-negative and finite.

Return value

A radial CanvasGradient initialized with the two specified circles.

Exceptions

NotSupportedError DOMException

Thrown when non-finite values are passed in parameter.

IndexSizeError DOMException

Thrown when a negative radius is passed in parameter.

Examples

Filling a rectangle with a radial gradient

This example initializes a radial gradient using the createRadialGradient() method. Three color stops between the gradient's two circles are then created. Finally, the gradient is assigned to the canvas context, and is rendered to a filled rectangle.

HTML

<canvas id="canvas" width="200" height="200"></canvas>

JavaScript

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

// Create a radial gradient
// The inner circle is at x=110, y=90, with radius=30
// The outer circle is at x=100, y=100, with radius=70
const gradient = ctx.createRadialGradient(110, 90, 30, 100, 100, 70);

// Add three color stops
gradient.addColorStop(0, "pink");
gradient.addColorStop(0.9, "white");
gradient.addColorStop(1, "green");

// Set the fill style and draw a rectangle
ctx.fillStyle = gradient;
ctx.fillRect(20, 20, 160, 160);

Result

Specifications

Browser compatibility

See also

• The interface defining this method: CanvasRenderingContext2D
• CanvasRenderingContext2D.createLinearGradient()
• CanvasRenderingContext2D.createConicGradient()