Benchmark: Deep merge lodash vs ramda vs deepmerge vs json clone

HTML Preparation code:

<script src="//cdn.jsdelivr.net/npm/ramda@latest/dist/ramda.min.js"></script>
<script src="https://raw.githubusercontent.com/lodash/lodash/4.17.15-npm/lodash.js"></script>
<script src="https://unpkg.com/deepmerge/dist/umd.js"></script>

Script Preparation code:

var obj1 = [
	{
		"id": "0001",
		"type": "donut",
		"name": "Cake",
		"ppu": 0.55,
		"batters":
			{
				"batter":
					[
						{ "id": "1001", "type": "Regular" },
						{ "id": "1002", "type": "Chocolate" },
						{ "id": "1003", "type": "Blueberry" },
						{ "id": "1004", "type": "Devil's Food" }
					]
			},
		"topping":
			[
				{ "id": "5001", "type": "None" },
				{ "id": "5002", "type": "Glazed" },
				{ "id": "5005", "type": "Sugar" },
				{ "id": "5007", "type": "Powdered Sugar" },
				{ "id": "5006", "type": "Chocolate with Sprinkles" },
				{ "id": "5003", "type": "Chocolate" },
				{ "id": "5004", "type": "Maple" }
			]
	},
	{
		"id": "0002",
		"type": "donut",
		"name": "Raised",
		"ppu": 0.55,
		"batters":
			{
				"batter":
					[
						{ "id": "1001", "type": "Regular" }
					]
			},
		"topping":
			[
				{ "id": "5001", "type": "None" },
				{ "id": "5002", "type": "Glazed" },
				{ "id": "5005", "type": "Sugar" },
				{ "id": "5003", "type": "Chocolate" },
				{ "id": "5004", "type": "Maple" }
			]
	},
	{
		"id": "0003",
		"type": "donut",
		"name": "Old Fashioned",
		"ppu": 0.55,
		"batters":
			{
				"batter":
					[
						{ "id": "1001", "type": "Regular" },
						{ "id": "1002", "type": "Chocolate" }
					]
			},
		"topping":
			[
				{ "id": "5001", "type": "None" },
				{ "id": "5002", "type": "Glazed" },
				{ "id": "5003", "type": "Chocolate" },
				{ "id": "5004", "type": "Maple" }
			]
	}
]

var obj2 = [
	{
		"id": "0001",
		"type": "donut",
		"name": "Cake",
		"ppu": 0.55,
		"batters":
			{
				"batter":
					[
						{ "id": "1001", "type": "Overwritten" },
						{ "id": "1002", "type": "Chocolate" },
						{ "id": "1003", "type": "Overwritten" },
						{ "id": "1004", "type": "Devil's Food" }
					]
			},
		"topping":
			[
				{ "id": "5001", "type": "Overwritten" },
				{ "id": "5002", "type": "Overwritten" },
				{ "id": "5005", "type": "Sugar" },
				{ "id": "5007", "type": "Powdered Sugar" },
				{ "id": "5006", "type": "Chocolate with Sprinkles" },
				{ "id": "5003", "type": "Chocolate" },
				{ "id": "5004", "type": "Overwritten" }
			]
	},
	{
		"id": "0002",
		"type": "Overwritten",
		"name": "Raised",
		"ppu": 0.55,
		"batters":
			{
				"batter":
					[
						{ "id": "1001", "type": "Overwritten" }
					]
			},
		"topping":
			[
				{ "id": "5001", "type": "None" },
				{ "id": "5002", "type": "Overwritten" },
				{ "id": "5005", "type": "Sugar" },
				{ "id": "5003", "type": "Chocolate" },
				{ "id": "5004", "type": "Maple" }
			]
	},
	{
		"id": "0003",
		"type": "Overwritten",
		"name": "Old Fashioned",
		"ppu": 0.55,
		"batters":
			{
				"batter":
					[
						{ "id": "1001", "type": "Overwritten" },
						{ "id": "1002", "type": "Chocolate" }
					]
			},
		"topping":
			[
				{ "id": "5001", "type": "None" },
				{ "id": "5002", "type": "Glazed" },
				{ "id": "5003", "type": "Chocolate" },
				{ "id": "5004", "type": "Maple" }
			]
	}
]

Tests:

Ramda.mergeDeepRight
R.mergeDeepRight(obj1, obj2)
Lodash.merge
_.merge(obj1, obj2)
deepmerge
deepmerge(obj1, obj2)
json clone
JSON.parse(JSON.stringify(obj1))
Lodash.merge immutable
_.merge({}, obj1, obj2)

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

Ramda.mergeDeepRight

508K/s

json clone

185K/s

Lodash.merge

88K/s

deepmerge

64K/s

Lodash.merge immutable

39K/s

Fastest: Ramda.mergeDeepRight (12.9x faster)

View exact numbers

✓ Ramda.mergeDeepRight: 508,244 ops/sec
• json clone: 184,549 ops/sec
• Lodash.merge: 88,382 ops/sec
• deepmerge: 63,792 ops/sec
• Lodash.merge immutable: 39,429 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
Ramda.mergeDeepRight
Lodash.merge
deepmerge
json clone
Lodash.merge immutable

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/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Windows

View result in a separate tab

Ramda.mergeDeepRight

508K/s

json clone

234K/s

Lodash.merge

88K/s

deepmerge

72K/s

Lodash.merge immutable

37K/s

View exact numbers

Test name	Executions per second
✓ Ramda.mergeDeepRight	508,244 Ops/sec
json clone	233,855 Ops/sec
Lodash.merge	88,382 Ops/sec
deepmerge	71,750 Ops/sec
Lodash.merge immutable	37,167 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Deep merge lodash vs ramda vs deepmerge vs json clone (version: 2)

Comparing performance of: `Ramda.mergeDeepRight vs Lodash.merge vs deepmerge vs json clone vs Lodash.merge immutable`

Created: 5 years ago by: Registered User

Go to the latest result

Ramda.mergeDeepRight

Lodash.merge

deepmerge

json clone

Lodash.merge immutable

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

Deep merge lodash vs ramda vs deepmerge vs json clone (version: 2)

Comparing performance of: Ramda.mergeDeepRight vs Lodash.merge vs deepmerge vs json clone vs Lodash.merge immutable

Created: 5 years ago by: Registered User

Go to the latest result

Ramda.mergeDeepRight

Lodash.merge

deepmerge

json clone

Lodash.merge immutable

Historical Performance Data aggregated from 7 community runs

Desktop Results:

Chrome 7 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

Related benchmarks

Comparing performance of: `Ramda.mergeDeepRight vs Lodash.merge vs deepmerge vs json clone vs Lodash.merge immutable`