Benchmark: lodash merge vs lodash/fp merge vs custom merge vs spread vs ramda merge

Script Preparation code:

var fp = _.noConflict();

function customMerge(a, b) {
  const result = {}
  for (const prop in a)
    if (a.hasOwnProperty(prop)) {
      result[prop] = b.hasOwnProperty(prop) 
        ? a[prop].constructor === Object 
          ? customMerge(a[prop], b[prop]) : b[prop] 
        : a[prop]
    }
  return result
}

Tests:

lodash merge
var a = { a: 'a', b: 'b', c: { a: 'ca', b: 'cb' }}; var b = { a: 'aa', c: {b: 'cbb'}}; var c = _.merge({}, a, b);
lodash/fp merge
var a = { a: 'a', b: 'b', c: { a: 'ca', b: 'cb' }}; var b = { a: 'aa', c: {b: 'cbb'}}; var c = fp.merge(b, a);
custom merge
var a = { a: 'a', b: 'b', c: { a: 'ca', b: 'cb' }}; var b = { a: 'aa', c: {b: 'cbb'}}; var c = customMerge(a, b)
spread
var a = { a: 'a', b: 'b', c: { a: 'ca', b: 'cb' }}; var b = { a: 'aa', c: {b: 'cbb'}}; var c = { ...a, ...b, c: { ...a.c, ...b.c, }, }
ramda merge
var a = { a: 'a', b: 'b', c: { a: 'ca', b: 'cb' }}; var b = { a: 'aa', c: {b: 'cbb'}}; var c = R.mergeDeepRight(a, b)

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

spread

21.9M/s

ramda merge

4.9M/s

custom merge

3.6M/s

lodash merge

1.3M/s

lodash/fp merge

1.0M/s

Fastest: spread (21.3x faster)

View exact numbers

✓ spread: 21,856,888 ops/sec
• ramda merge: 4,913,080 ops/sec
• custom merge: 3,580,622 ops/sec
• lodash merge: 1,260,953 ops/sec
• lodash/fp merge: 1,027,525 ops/sec

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

Test case name	Result
lodash merge
lodash/fp merge
custom merge
spread
ramda merge

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36

Browser/OS: Chrome 125 on Mac OS X 10.15.7

View result in a separate tab

spread

22.4M/s

ramda merge

4.9M/s

custom merge

3.6M/s

lodash merge

1.3M/s

lodash/fp merge

1.0M/s

View exact numbers

Test name	Executions per second
✓ spread	22,367,880 Ops/sec
ramda merge	4,945,838 Ops/sec
custom merge	3,617,925 Ops/sec
lodash merge	1,293,449 Ops/sec
lodash/fp merge	1,044,428 Ops/sec

lodash merge vs lodash/fp merge vs custom merge vs spread vs ramda merge (version: 0)

Comparing performance of: `lodash merge vs lodash/fp merge vs custom merge vs spread vs ramda merge`

Created: 2 years ago by: Guest

Go to the latest result

lodash merge

lodash/fp merge

custom merge

spread

ramda merge

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

lodash merge vs lodash/fp merge vs custom merge vs spread vs ramda merge (version: 0)

Comparing performance of: lodash merge vs lodash/fp merge vs custom merge vs spread vs ramda merge

Created: 2 years ago by: Guest

Go to the latest result

lodash merge

lodash/fp merge

custom merge

spread

ramda merge

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: `lodash merge vs lodash/fp merge vs custom merge vs spread vs ramda merge`