Run results for: Object vs Object.seal

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.0 Safari/605.1.15

Browser: Safari 26

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 7 months ago

Test name	Executions per second
normal	6789350.0 Ops/sec
seal	4304408.0 Ops/sec

Script Preparation code:

var normal = {
  x: 1,
  y: 2,
  z: 0
};
var seal = Object.seal({
  x: 1,
  y: 2,
  z: 0
});
var tmp = {
  x: 0,
  y: 0,
  z: 0
};
var k;
var v;

Tests:

normal
normal.z = normal.x + normal.y; for (k in normal) { tmp[k] = normal[k]; } for ([k, v] of Object.entries(normal)) { tmp[k] = v; }
seal
seal.z = seal.x + seal.y; for (k in seal) { tmp[k] = seal[k]; } for ([k, v] of Object.entries(seal)) { tmp[k] = v; }

Run results for: Object vs Object.seal

JS Javascript Normal Object vs Object.seal performance

normal

seal