This is the fastest deep-clone implementation for JSON objects - faster than structuredClone, JSON.parse(JSON.stringify(obj)) and other implementations.

This package is ESM-only.

• Dependencies: 0
• Bundle size (minified and gzipped): 316 Bytes
• Module count: 1

It avoids recursion in favor of a stack, in order to keep the memory usage low.

Performance comparison

| Method | Ops/sec | |-------------------------------------------------------------------------------------------------------------------|-----------| | This package (iterative deep clone) | 3.560.061 | | recursive deep clone | 3.476.448 | | fastest-json-copy v2 | 1.523.427 | | JSON.stringify | 1.465.516 | | fastest-json-copy v1 | 1.320.249 | | jsondiffpatch.clone | 1.245.459 | | structuredClone | 789.100 |

Run it yourself: https://www.measurethat.net/Benchmarks/ShowResult/534839 (this package is deepCopyObjectIterative in that comparison)

Installation

pnpm install fastest-deep-clone-json

or

npm install fastest-deep-clone-json

Usage

import { deepCloneJson } from 'fastest-deep-clone-json';

const obj = { a: 1, b: { c: 2 } };

const cloned = deepCloneJson(obj);

console.log(cloned); // { a: 1, b: { c: 2 } }

This library will only work with JSON-serialized objects. It does not handle data types like Date, Map, Set, BigInt, Symbol, Function etc etc. The goal is to provide the fastest deep-clone implementation for JSON objects.