Benchmark: Fastest way to list children: childNodes vs children vs firstChild/nextSibling vs firstElementChild/nextElementSibling v2

Fastest way to list children: childNodes vs children vs firstChild/nextSibling vs firstElementChild/nextElementSibling v2 (version: 0)

Result: firstElementChild is the fastest yielding 3-4X performance. With lastElementChild close 2nd. Other observations: doing for loop i-- with children shows ~150% higher performance vs i++. And unloading it into a variable prior yields another ~200% boost

Comparing performance of: `childNodes foreach vs children (direct) vs firstChild nextSibling vs firstElementChild nextElementChild vs ChildNodes for (into variable) vs children-- (direct) vs ChildNodes for-- (into variable) vs ChildNodes for-- (direct) vs lastElementChild previousElementChild vs children-- (into variable)`

Created: 4 years ago by: Guest

Go to the latest result

HTML Preparation code:

<html>

<body>
    <div id='test'>
        <div name='a'></div>
        <div name='b'></div>
        <div name='c'></div>
    </div>
</body>

</html>

Script Preparation code:

var parent = document.getElementById('test');

Tests:

childNodes foreach
parent.childNodes.forEach(function (node) { let n = node; });
children (direct)
for (let i = 0; i < parent.children.length; i++) { let n = parent.children[i]; }
firstChild nextSibling
let elem = parent.firstChild; do { let n = elem; } while (elem = elem.nextSibling)
firstElementChild nextElementChild
let elem = parent.firstElementChild; do { let n = elem; } while (elem = elem.nextElementSibling)
ChildNodes for (into variable)
let children = parent.childNodes; for (let i = 0; i < children.length; i++) { let n = children[i]; }
children-- (direct)
for (let i = parent.children.length-1; i >= 0; i--) { let n = parent.children[i]; }
ChildNodes for-- (into variable)
for (let i = parent.childNodes.length-1; i >= 0; i--) { let n = parent.childNodes[i]; }
ChildNodes for-- (direct)
let children = parent.childNodes; for (let i = children.length-1; i >= 0; i--) { let n = children[i]; }
lastElementChild previousElementChild
let elem = parent.lastElementChild; do { let n = elem; } while (elem = elem.previousElementSibling)
children-- (into variable)
let children = parent.children for (let i = children.length-1; i >= 0; i--) { let n = children[i]; }

Historical Performance Data aggregated from 49 community runs

Desktop Results:

Chrome 44 runs

firstElementChild nextElementChild

9.2M/s

lastElementChild previousElementChild

8.6M/s

firstChild nextSibling

6.4M/s

children-- (into variable)

4.8M/s

ChildNodes for-- (direct)

3.1M/s

ChildNodes for (into variable)

2.6M/s

children-- (direct)

2.3M/s

children (direct)

1.4M/s

ChildNodes for-- (into variable)

1.3M/s

childNodes foreach

969K/s

Fastest: firstElementChild nextElementChild (9.5x faster)

View exact numbers

✓ firstElementChild nextElementChild: 9,235,367 ops/sec
• lastElementChild previousElementChild: 8,606,398 ops/sec
• firstChild nextSibling: 6,399,250 ops/sec
• children-- (into variable): 4,780,996 ops/sec
• ChildNodes for-- (direct): 3,088,043 ops/sec
• ChildNodes for (into variable): 2,595,681 ops/sec
• children-- (direct): 2,284,672 ops/sec
• children (direct): 1,375,901 ops/sec
• ChildNodes for-- (into variable): 1,274,656 ops/sec
• childNodes foreach: 968,719 ops/sec

Firefox 5 runs

firstElementChild nextElementChild

48.0M/s

lastElementChild previousElementChild

45.6M/s

firstChild nextSibling

22.1M/s

children-- (into variable)

11.4M/s

children-- (direct)

8.9M/s

ChildNodes for-- (direct)

6.0M/s

children (direct)

5.6M/s

ChildNodes for-- (into variable)

5.0M/s

ChildNodes for (into variable)

4.2M/s

childNodes foreach

3.4M/s

Fastest: firstElementChild nextElementChild (14.2x faster)

View exact numbers

✓ firstElementChild nextElementChild: 48,043,380 ops/sec
• lastElementChild previousElementChild: 45,576,992 ops/sec
• firstChild nextSibling: 22,137,484 ops/sec
• children-- (into variable): 11,370,601 ops/sec
• children-- (direct): 8,896,792 ops/sec
• ChildNodes for-- (direct): 6,044,884 ops/sec
• children (direct): 5,613,930 ops/sec
• ChildNodes for-- (into variable): 5,037,688 ops/sec
• ChildNodes for (into variable): 4,171,763 ops/sec
• childNodes foreach: 3,375,417 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
childNodes foreach
children (direct)
firstChild nextSibling
firstElementChild nextElementChild
ChildNodes for (into variable)
children-- (direct)
ChildNodes for-- (into variable)
ChildNodes for-- (direct)
lastElementChild previousElementChild
children-- (into variable)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36 Edg/151.0.0.0

Browser/OS: Chrome 151 on Windows

View result in a separate tab

firstElementChild nextElementChild

15.4M/s

lastElementChild previousElementChild

14.5M/s

children-- (into variable)

8.4M/s

firstChild nextSibling

7.2M/s

ChildNodes for-- (direct)

4.0M/s

children-- (direct)

4.0M/s

ChildNodes for (into variable)

3.5M/s

children (direct)

2.4M/s

ChildNodes for-- (into variable)

2.3M/s

childNodes foreach

1.3M/s

View exact numbers

Test name	Executions per second
✓ firstElementChild nextElementChild	15,355,374 Ops/sec
lastElementChild previousElementChild	14,529,700 Ops/sec
children-- (into variable)	8,430,285 Ops/sec
firstChild nextSibling	7,216,320 Ops/sec
ChildNodes for-- (direct)	4,044,752 Ops/sec
children-- (direct)	4,030,267 Ops/sec
ChildNodes for (into variable)	3,468,432 Ops/sec
children (direct)	2,427,461 Ops/sec
ChildNodes for-- (into variable)	2,267,155 Ops/sec
childNodes foreach	1,336,437 Ops/sec

Fastest way to list children: childNodes vs children vs firstChild/nextSibling vs firstElementChild/nextElementSibling v2 (version: 0)

Result: firstElementChild is the fastest yielding 3-4X performance. With lastElementChild close 2nd. Other observations: doing for loop i-- with children shows ~150% higher performance vs i++. And unloading it into a variable prior yields another ~200% boost

Created: 4 years ago by: Guest

Go to the latest result

childNodes foreach

children (direct)

firstChild nextSibling

firstElementChild nextElementChild

ChildNodes for (into variable)

children-- (direct)

ChildNodes for-- (into variable)

ChildNodes for-- (direct)

lastElementChild previousElementChild

children-- (into variable)

Historical Performance Data aggregated from 49 community runs

Desktop Results:

Chrome 44 runs

Firefox 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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