Run results for: OffsetScreenCanvas.measureText VS. Canvas.measureText

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36

Browser: Chrome 136

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

measureText via Canvas

48K/s

measureText via OffsetScreenCanvas

14K/s

View exact numbers

Test name	Executions per second
✓ measureText via Canvas	48,159 Ops/sec
measureText via OffsetScreenCanvas	14,198 Ops/sec

Script Preparation code:

const font = '12px sans-serif';
const testTexts = window.testTexts = '国口永水〇0o123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('');

window.measureText = (() => {
  const canvas = document.createElement('canvas');
  const ctx = canvas.getContext('2d');
  ctx.font = font;
  return (txt) => ctx.measureText(txt);
})();

window.oscMeasureText = (() => {
  const canvas = new window.OffscreenCanvas(0, 0);
  const ctx = canvas.getContext('2d');
  ctx.font = font;
  return (txt) => ctx.measureText(txt);
})();

Tests:

measureText via Canvas
testTexts.map(txt => measureText(txt))
measureText via OffsetScreenCanvas
testTexts.map(txt => oscMeasureText(txt))