JSFiddle - React, Tailwind, and code Playground

HTML

<canvas id="canvas" width="500" height="500"></canvas>

CSS

body {
  background-color: black;
}

JavaScript

var canvas = document.getElementById('canvas');
var cntx = canvas.getContext('2d');

cntx.strokeStyle = '#ffffff';

cntx.lineWidth = 1;

// с 0.5px
cntx.moveTo(1.5, 0);
cntx.lineTo(1.5, 100);
cntx.stroke();

// без 0.5 px
cntx.moveTo(50, 0);
cntx.lineTo(50, 100);
cntx.stroke();