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CanvasRenderingContext2D: strokeStyle property

files/en-us/web/api/canvasrenderingcontext2d/strokestyle/index.md

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{{APIRef("Canvas API")}}

The CanvasRenderingContext2D.strokeStyle property of the Canvas 2D API specifies the color, gradient, or pattern to use for the strokes (outlines) around shapes. The default is black.

[!NOTE] For more examples of stroke and fill styles, see Applying styles and color in the Canvas tutorial.

Value

One of the following:

  • color
    • : A string parsed as CSS {{cssxref("<color>")}} value.
  • gradient
    • : A {{domxref("CanvasGradient")}} object (a linear or radial gradient).
  • pattern
    • : A {{domxref("CanvasPattern")}} object (a repeating image).

Examples

Changing the stroke color of a shape

This example applies a blue stroke color to a rectangle.

HTML

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

JavaScript

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

ctx.strokeStyle = "blue";
ctx.strokeRect(10, 10, 100, 100);

Result

{{ EmbedLiveSample('Changing_the_stroke_color_of_a_shape', 700, 160) }}

Creating multiple stroke colors using loops

In this example, we use two for loops and the {{domxref("CanvasRenderingContext2D.arc", "arc()")}} method to draw a grid of circles, each having a different stroke color. To achieve this, we use the two variables i and j to generate a unique RGB color for each circle, and only modify the green and blue values. (The red channel has a fixed value.)

html
<canvas id="canvas" width="150" height="150"></canvas>
js
const ctx = document.getElementById("canvas").getContext("2d");

for (let i = 0; i < 6; i++) {
  for (let j = 0; j < 6; j++) {
    ctx.strokeStyle = `rgb(
        0
        ${Math.floor(255 - 42.5 * i)}
        ${Math.floor(255 - 42.5 * j)})`;
    ctx.beginPath();
    ctx.arc(12.5 + j * 25, 12.5 + i * 25, 10, 0, Math.PI * 2, true);
    ctx.stroke();
  }
}

The result looks like this:

{{EmbedLiveSample("Creating_multiple_stroke_colors_using_loops", "", "180")}}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

In WebKit- and Blink-based browsers, the non-standard and deprecated method ctx.setStrokeColor() is implemented in addition to this property.

js
setStrokeColor(color);
setStrokeColor(color, alpha);
setStrokeColor(grayLevel);
setStrokeColor(grayLevel, alpha);
setStrokeColor(r, g, b, a);
setStrokeColor(c, m, y, k, a);

See also

  • The interface defining this property: {{domxref("CanvasRenderingContext2D")}}
  • {{domxref("CanvasGradient")}}
  • {{domxref("CanvasPattern")}}