JS Deep Clone Benchmark

This is a benchmark for JS deep clone libraries.

Clone Support Matrix

Library	json	json-circular	regexp	date	custom-class	array-buffer	buffer	map-set
@ungap/structured-clone	✅	✅	✅	✅	❌	✅	❌	✅
clone	✅	✅	✅	✅	✅	❌	✅	✅
clone-deep	✅	❌	✅	✅	❌	❌	❌	❌
copy-anything	✅	❌	❌	❌	❌	❌	❌	❌
core-js/structured-clone	✅	✅	✅	✅	❌	✅	❌	✅
deepcopy	✅	✅	✅	✅	❌	❌	✅	✅
es-toolkit.cloneDeep	✅	✅	✅	✅	✅	✅	❌	✅
fast-copy	✅	✅	✅	✅	✅	✅	❌	✅
fastest-json-copy	✅	❌	❌	❌	❌	❌	❌	❌
JSON.stringify/parse	✅	❌	❌	❌	❌	❌	❌	❌
jsondiffpatch.clone	✅	❌	✅	✅	❌	❌	❌	❌
just-clone	✅	❌	✅	✅	❌	❌	❌	✅
klona	✅	❌	✅	✅	✅	✅	✅	✅
klona/json	✅	❌	❌	❌	❌	❌	❌	❌
klona/lite	✅	❌	✅	✅	✅	❌	❌	❌
lodash.cloneDeep	✅	✅	✅	✅	✅	❌	❌	✅
nano-copy	✅	✅	✅	✅	✅	✅	✅	✅
nanoclone	✅	✅	✅	✅	❌	❌	❌	✅
plain-object-clone	✅	❌	❌	❌	❌	❌	❌	❌
ramda.clone	✅	✅	✅	✅	✅	❌	❌	❌
rfdc	✅	✅	⚠️	✅	⚠️	⚠️	✅	✅
structuredClone	✅	✅	✅	✅	❌	✅	❌	✅

⚠️: need customize manually to support

Benchmark Results

for Bun please refer to Bun

cpu: 13th Gen Intel(R) Core(TM) i5-13400F

runtime: node 26.7.0 (x64-win32)

json

Library	small (ops/s)	large (ops/s)
@ungap/structured-clone	45,654	5,194
clone	20,931	362
clone-deep	107,516	1,810
clone(circular)	18,028	2,000
copy-anything	33,430	553
core-js/structured-clone	15,739	1,812
deepcopy	19,353	2,103
es-toolkit.cloneDeep	61,747	6,014
fast-copy	123,655	12,019
fastest-json-copy	224,319	3,783
JSON.stringify/parse	90,517	1,604
jsondiffpatch.clone	323,775	5,987
just-clone	24,392	419
klona	260,069	4,346
klona/json	330,567	5,592
klona/lite	299,938	4,974
lodash.cloneDeep	34,606	3,565
nano-copy	115,032	11,960
nanoclone	144,277	14,958
plain-object-clone	54,090	962
ramda.clone	10,341	634
rfdc	169,122	2,794
rfdc(circles)	156,791	2,499
structuredClone	46,059	5,205

json-circular

Library	small (ops/s)	large (ops/s)
@ungap/structured-clone	619,282	885
clone(circular)	397,530	194
core-js/structured-clone	374,278	275
deepcopy	630,246	375
es-toolkit.cloneDeep	1,626,825	1,196
fast-copy	3,121,016	1,851
lodash.cloneDeep	1,019,148	662
nano-copy	2,809,979	1,965
nanoclone	3,781,593	2,331
ramda.clone	278,241	72
rfdc(circles)	4,034,051	2,553
structuredClone	610,232	893

regexp

Library	small (ops/s)	large (ops/s)
@ungap/structured-clone	104,200	13,255
clone	54,245	859
clone-deep	171,252	2,759
clone(circular)	44,422	4,701
core-js/structured-clone	46,594	5,809
deepcopy	51,917	6,986
es-toolkit.cloneDeep	153,386	17,024
fast-copy	170,342	19,032
jsondiffpatch.clone	91,977	1,730
just-clone	97,950	1,482
klona	352,647	6,083
klona/lite	390,972	6,460
lodash.cloneDeep	38,244	3,722
nano-copy	161,864	20,412
nanoclone	233,102	25,067
ramda.clone	41,056	4,227
rfdc(with RegExp)	311,976	5,195
structuredClone	100,441	12,947

date

Library	small (ops/s)	large (ops/s)
@ungap/structured-clone	56,368	16,072
clone	27,170	486
clone-deep	82,890	1,509
clone(circular)	22,491	3,370
core-js/structured-clone	14,832	2,260
deepcopy	28,581	6,024
es-toolkit.cloneDeep	75,147	19,875
fast-copy	82,188	15,356
jsondiffpatch.clone	279,275	5,252
just-clone	51,726	942
klona	140,989	2,588
klona/lite	145,591	2,614
lodash.cloneDeep	32,967	5,140
nano-copy	105,413	18,059
nanoclone	137,265	25,314
ramda.clone	18,652	3,143
rfdc	204,633	3,616
rfdc(circles)	190,180	3,453
structuredClone	56,328	16,238

custom-class

Library	small (ops/s)	large (ops/s)
clone	388,417	1,191
clone(circular)	346,297	766
es-toolkit.cloneDeep	1,123,251	3,257
fast-copy	1,195,925	3,753
klona	2,014,139	6,670
klona/lite	2,184,488	7,112
lodash.cloneDeep	696,056	1,751
nano-copy	1,637,195	5,080
ramda.clone	225,226	394
rfdc(with Custom Classes)	3,529,579	10,429

array-buffer

Library	small (ops/s)	large (ops/s)
@ungap/structured-clone	40,989	12
core-js/structured-clone	33,546	37
es-toolkit.cloneDeep	29,877	23
fast-copy	49,790	40
klona	48,387	39
nano-copy	51,624	39
rfdc(with ArrayBuffer)	49,892	39
structuredClone	39,789	12

buffer

Library	small (ops/s)	large (ops/s)
clone	54,105	42
clone(circular)	59,384	42
deepcopy	33,445	23
klona	52,213	42
nano-copy	58,714	42
rfdc	54,635	42
rfdc(circles)	64,285	42

buffer-zero-copy

Library	small (ops/s)	large (ops/s)
es-toolkit.cloneDeep	1,016,738	1,006,102
lodash.cloneDeep	421,283	422,424

map-set

Library	small (ops/s)	large (ops/s)
@ungap/structured-clone	126,996	13,370
clone	115,352	10,942
clone(circular)	94,512	8,729
core-js/structured-clone	47,656	4,812
deepcopy	95,692	9,197
es-toolkit.cloneDeep	295,602	27,700
fast-copy	269,128	24,648
just-clone	114,678	24,683
klona	415,678	38,509
lodash.cloneDeep	81,298	6,333
nano-copy	164,803	16,045
nanoclone	452,121	40,374
rfdc	172,712	21,794
rfdc(circles)	150,364	21,389
structuredClone	120,952	13,541