web api instance property

CanvasRenderingContext2D: lineWidth property

The CanvasRenderingContext2D.lineWidth property of the Canvas 2D API sets the thickness of lines.

[!NOTE] Lines can be drawn with the stroke(), strokeRect(), and strokeText() methods.

Value

A number specifying the line width, in coordinate space units. Zero, negative, Infinity, and NaN values are ignored. This value is 1.0 by default.

Examples

Changing line width

This example draws a line and a rectangle, using a line width of 15 units.

HTML

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

JavaScript

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

ctx.lineWidth = 15;

ctx.beginPath();
ctx.moveTo(20, 20);
ctx.lineTo(130, 130);
ctx.rect(40, 40, 70, 70);
ctx.stroke();

Result

Interactive exampleOpen the canonical MDN source to run this embedded demo.

More examples

For more examples and explanation about this property, see Applying styles and color in the Canvas Tutorial.

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.