Run results for: Translucent RGBa vs Opaque RGBa with global alpha

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser: Chrome 130

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

Translucent RGBa

1.5M/s

Opaque RGBa with globalAlpha

1.3M/s

View exact numbers

Test name	Executions per second
✓ Translucent RGBa	1,483,198 Ops/sec
Opaque RGBa with globalAlpha	1,341,462 Ops/sec

HTML Preparation code:

<canvas id="canvasOne" width="400" height="400"></canvas>
<canvas id="canvasTwo" width="400" height="400"></canvas>

Script Preparation code:

var canvasOne = document.getElementById("canvasOne");
var ctxOne = canvasOne.getContext("2d", { alpha: false });

var canvasTwo = document.getElementById("canvasTwo");
var ctxTwo = canvasTwo.getContext("2d", { alpha: false });

Tests:

Translucent RGBa
ctxOne.clearRect(0, 0, 400, 400); ctxOne.beginPath(); ctxOne.fillStyle = 'rgba(231, 76, 60, 0.5)'; ctxOne.arc(200, 200, 100, 0, Math.PI * 2, true); ctxOne.fill();
Opaque RGBa with globalAlpha
ctxTwo.clearRect(0, 0, 400, 400); ctxTwo.beginPath(); ctxTwo.fillStyle = 'rgba(231, 76, 60, 1)'; ctxTwo.globalAlpha = 0.5; ctxTwo.arc(200, 200, 100, 0, Math.PI * 2, true); ctxTwo.fill();