Run results for: Large Canvas Performance Test

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36

Browser: Chrome 127

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

fillRect

2K/s

putImage

30/s

View exact numbers

Test name	Executions per second
✓ fillRect	1,837 Ops/sec
putImage	30 Ops/sec

HTML Preparation code:

<canvas id="c" width="5000" height="5000"></canvas>

Script Preparation code:

$c = document.getElementById('c');
$ctx = $c.getContext('2d');
$ctx.clearRect(0, 0, 5000, 5000);
$px = $ctx.createImageData(1, 1);
$pxls = [];
for (var i=0; i<10000; ++i) $pxls.push({
   x: Math.random() * 5000 << 0,
   y: Math.random() * 5000 << 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:

fillRect
for (var i=500;i--;){ var px = $pxls[$i++ % 10000]; $ctx.fillStyle = 'rgba(' + px.r + ',' + px.g + ',' + px.b + ',' + (px.a / 255) + ')'; $ctx.fillRect(px.x, px.y, 1, 1); }
putImage
var image = $ctx.createImageData($c.width, $c.height); for (var i=500;i--;){ var px=$pxls[$i++ % 10000], d=$px.data; var _pidx = i * 4; image.data[_pidx] = px.r; image.data[_pidx+1] = px.g; image.data[_pidx+2] = px.b; image.data[_pidx+3] = px.a; } $ctx.putImageData(image, 0, 0);

Run results for: Large Canvas Performance Test

Comparing performance of: fillRect vs putImage on large canvas

fillRect

putImage