Run results for: Canvas Pixel vs Fill rect

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.81 Safari/537.36

Browser: Chrome 94

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
1*1 fillRect/concat	0.4 Ops/sec
Image Data	0.9 Ops/sec

HTML Preparation code:

<canvas id="c" width="1000" height="500"></canvas>

Script Preparation code:

$c = document.getElementById('c');
$ctx = $c.getContext('2d');
$ctx.clearRect(0, 0, 10000, 500);
$px = $ctx.createImageData(1000, 500);
$pxls = [];
for (var i=0; i<500000; ++i) $pxls.push({
   x: Math.random() * 1000 << 0,
   y: Math.random() * 500 << 0,
   r: Math.random() * 255 << 0,
   g: Math.random() * 255 << 0,
   b: Math.random() * 255 << 0,
   a: Math.random() * 128 << 0 + 128
});
$i = 0;

Tests:

1*1 fillRect/concat
for (var i=1000;i--;){ for(var j=500;j--;){ var px = $pxls[i*j] $ctx.fillStyle = 'rgba(' + px.r + ',' + px.g + ',' + px.b + ',' + (px.a / 255) + ')'; $ctx.fillRect(px.x, px.y, 1, 1); } }
Image Data
for (var i=0; i<500000; ++i){ var px=$pxls[i], d=$px.data[i]; d[0] = px.r; d[1] = px.g; d[2] = px.b; d[3] = px.a; } $ctx.putImageData($px, 1000,500);

Run results for: Canvas Pixel vs Fill rect

1*1 fillRect/concat

Image Data