CanvasRenderingContext2D: fillRect() method

The CanvasRenderingContext2D.fillRect() method of the Canvas 2D API draws a rectangle that is filled according to the current {{domxref("CanvasRenderingContext2D.fillStyle", "fillStyle")}}.

This method draws directly to the canvas without modifying the current path, so any subsequent {{domxref("CanvasRenderingContext2D.fill()", "fill()")}} or {{domxref("CanvasRenderingContext2D.stroke()", "stroke()")}} calls will have no effect on it.

Syntax

js-nolint

fillRect(x, y, width, height)

The fillRect() method draws a filled rectangle whose starting point is at (x, y) and whose size is specified by width and height. The fill style is determined by the current fillStyle attribute.

Parameters

x
- : The x-axis coordinate of the rectangle's starting point.
y
- : The y-axis coordinate of the rectangle's starting point.
width
- : The rectangle's width. Positive values are to the right, and negative to the left.
height
- : The rectangle's height. Positive values are down, and negative are up.

Return value

None ({{jsxref("undefined")}}).

Examples

A simple filled rectangle

This example draws a filled green rectangle using the fillRect() method.

HTML

html

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

JavaScript

The rectangle's top-left corner is at (20, 10). It has a width of 150 and a height of 100.

const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
ctx.fillStyle = "green";
ctx.fillRect(20, 10, 150, 100);

Result

Filling the whole canvas

This code snippet fills the entire canvas with a rectangle. This is often useful for creating a background, on top of which other things may then be drawn. To achieve this, the dimensions of the rectangle are set to equal the {{HtmlElement("canvas")}} element's width and height attributes.

const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
ctx.fillRect(0, 0, canvas.width, canvas.height);