Benchmark: Reading from objects - Seal vs Unsealed

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

function new_struct() {
    return {
        a: Math.random(),
        b: Math.random(),
        c: Math.random(),
        d: Math.random(),
    };
}

var structs1 = new Array(10000);
var structs2 = new Array(10000);

var new_values = new Array(10000);
var results = new Array(10000);

for (let i = 0; i < 10000; i++) {
    structs1[i] = new_struct();
    structs2[i] = Object.seal(
        Object.assign(new_struct(), structs1[i])
    );
    results[i] = new_struct();
    new_values[i] = new_struct();
}

Tests:

Sealed
for (let i = 0; i < results.length; i++) { results[i].a = structs1[i].a + new_values[i].a; results[i].b = structs1[i].b + new_values[i].b; results[i].c = structs1[i].c + new_values[i].c; results[i].d = structs1[i].d + new_values[i].d; }
Unsealed
for (let i = 0; i < results.length; i++) { results[i].a = structs2[i].a + new_values[i].a; results[i].b = structs2[i].b + new_values[i].b; results[i].c = structs2[i].c + new_values[i].c; results[i].d = structs2[i].d + new_values[i].d; }

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Firefox 7 runs

Unsealed

12K/s

Sealed

11K/s

View exact numbers

✓ Unsealed: 11,577 ops/sec
• Sealed: 11,471 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Sealed
Unsealed

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36

Browser/OS: Chrome 139 on Linux

View result in a separate tab

Unsealed

4K/s

Sealed

4K/s

View exact numbers

Test name	Executions per second
✓ Unsealed	3,912 Ops/sec
Sealed	3,757 Ops/sec

Reading from objects - Seal vs Unsealed (version: 6)

Comparing performance of: `Sealed vs Unsealed`

Created: one year ago by: Registered User

Go to the latest result

Sealed

Unsealed

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Firefox 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Reading from objects - Seal vs Unsealed (version: 6)

Comparing performance of: Sealed vs Unsealed

Created: one year ago by: Registered User

Go to the latest result

Sealed

Unsealed

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Firefox 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `Sealed vs Unsealed`