Benchmark: forEach vs for of (with Iterator)

HTML Preparation code:

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

Script Preparation code:

/*your preparation JavaScript code goes here
To execute async code during the script preparation, wrap it as function globalMeasureThatScriptPrepareFunction, example:*/
async function globalMeasureThatScriptPrepareFunction() {
    // This function is optional, feel free to remove it.
    // await someThing();
}

Tests:

forEach
/*When writing async/deferred tests, use `deferred.resolve()` to mark test as done*/ const arr = new Array(1000); arr[Symbol.iterator]().forEach(v => { var a = v });
for of
const arr = new Array(1000); for (var v of arr) { var a = v }

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

for of

1.2M/s

forEach

42K/s

Fastest: for of (27.5x faster)

View exact numbers

✓ for of: 1,162,324 ops/sec
• forEach: 42,277 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
forEach
for of

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36

Browser/OS: Chrome 138 on Windows

View result in a separate tab

for of

1.8M/s

forEach

100K/s

View exact numbers

Test name	Executions per second
✓ for of	1,819,680 Ops/sec
forEach	99,892 Ops/sec

forEach vs for of (with Iterator) (version: 1)

Comparing performance of: `forEach vs for of`

Created: one year ago by: Guest

Go to the latest result

forEach

for of

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

forEach vs for of (with Iterator) (version: 1)

Comparing performance of: forEach vs for of

Created: one year ago by: Guest

Go to the latest result

forEach

for of

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `forEach vs for of`