The CanvasRenderingContext2D.lineJoin property of the Canvas 2D API determines the shape used to join two line segments where they meet.

This property has no effect wherever two connected segments have the same direction, because no joining area will be added in this case. Degenerate segments with a length of zero (i.e., with all endpoints and control points at the exact same position) are also ignored.

Note: Lines can be drawn with the stroke()strokeRect(), and strokeText() methods.


ctx.lineJoin = "bevel" || "round" || "miter";


There are three possible values for this property: "round", "bevel", and "miter". The default is "miter".

Rounds off the corners of a shape by filling an additional sector of disc centered at the common endpoint of connected segments. The radius for these rounded corners is equal to the line width.
Fills an additional triangular area between the common endpoint of connected segments, and the separate outside rectangular corners of each segment.
Connected segments are joined by extending their outside edges to connect at a single point, with the effect of filling an additional lozenge-shaped area. This setting is affected by the miterLimit property. Default value.


Changing the joins in a path

This example applies rounded line joins to a path.


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


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

ctx.lineWidth = 20;
ctx.lineJoin = 'round';
ctx.moveTo(20, 20);
ctx.lineTo(190, 100);
ctx.lineTo(280, 20);
ctx.lineTo(280, 150);


Comparison of line joins

The example below draws three different paths, demonstrating each of the three lineJoin options.

var ctx = document.getElementById('canvas').getContext('2d');
var lineJoin = ['round', 'bevel', 'miter'];
ctx.lineWidth = 10;

for (let i = 0; i < lineJoin.length; i++) {
  ctx.lineJoin = lineJoin[i];
  ctx.moveTo(-5, 5 + i * 40);
  ctx.lineTo(35, 45 + i * 40);
  ctx.lineTo(75, 5 + i * 40);
  ctx.lineTo(115, 45 + i * 40);
  ctx.lineTo(155, 5 + i * 40);
ScreenshotLive sample


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

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
lineJoinChrome Full support YesEdge Full support 12Firefox Full support 1.5IE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes


Full support  
Full support
  • In WebKit- and Blink-based Browsers, a non-standard and deprecated method ctx.setLineJoin() is implemented in addition to this property.

See also