Run results for: alpha false

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_3_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.3.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.3.2

Device Platform: Mobile

Date tested: one year ago

true

790K/s

false

35K/s

View exact numbers

Test name	Executions per second
✓ true	789,750 Ops/sec
false	35,136 Ops/sec

HTML Preparation code:

<div style="width: 830; height: 200; background-color: red;"> <canvas id="canvas1" width="400" height="400"></canvas> <canvas id="canvas2" width="400" height="400"></canvas> </div> <style> canvas { border: 1px solid black; } </style>

Script Preparation code:

var can = document.getElementById('canvas1');
var ctx = can.getContext('2d');
ctx.fillRect(50,50,50,50);
ctx.clearRect(0,0,400,400);

var can2 = document.getElementById('canvas2');
var ctx2 = can2.getContext('2d', {alpha: false} );
ctx2.fillRect(50,50,50,50);
ctx2.clearRect(0,0,400,400);

Tests:

false
ctx2.fillStyle = 'rgba(255, 255, 255, 0.3)'; ctx2.fillRect(0,0,400,400);
true
ctx.fillStyle = 'rgba(255, 255, 255, 0.3)'; ctx.fillRect(0,0,400,400);