# planttheidea/fast-copy

A blazing fast deep object copier

Repository: https://github.com/planttheidea/fast-copy
Canonical: https://ross.abutalabs.com/products/fast-copy
Language: JavaScript
License: MIT
License Family: permissive
Last push: 2026-09-02T16:48:58+00:00

## Health v2 (maintenance only)
Score: 100/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 100, release rhythm 100, longevity 100
- inputs: {"age_days": 3036, "days_push": 0, "days_rel": 0, "gap_med": 20.0, "n_releases_24m": 9}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1159, forks 26 (observed 2026-09-03T02:15:16.934388+00:00)

## What it is
fast-copy is a JavaScript library providing a highly performant deep copy (clone) of objects, arrays, Maps, Sets, and other complex structures, including circular references. It offers a strict copy mode and a createCopier API for building custom copiers.

## Use cases
- deep clone a javascript object
- copy nested objects with circular references
- fast deep copy for state management
- clone maps and sets deeply
- create a custom deep copier for specific types
- copy objects without mutating the original

## When to choose
- you need the fastest available deep clone in JavaScript benchmarks
- your data includes Maps, Sets, dates, or circular references
- you want a tiny, dependency-light utility with a customizable copier API

## When to avoid
- you only need a shallow copy (Object.assign or spread suffices)
- you need structuredClone's exact semantics or transferable support
- you require copying non-enumerable properties with high performance (copyStrict is much slower)

## Facets
- artifact type: library
- maturity: active
- function: serialization, developer-tools
- domain: developer-tools, web-development
- platform: browser, cross-platform
- tags: deep-clone, deep-copy, javascript, performance, circular-references, immutable-state, algorithms, nodejs

## Member repositories
- planttheidea/fast-copy (main) score 100

## Provenance
- Observed fields: from GitHub, fetched 2026-09-03T02:15:16.934388+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:31:43.547120+00:00, confidence not recorded.
  - readme: https://github.com/planttheidea/fast-copy (fetched 2026-09-03T02:15:16.934388+00:00, sha 201b13cbe8c7)
  - registry_npm: https://registry.npmjs.org/fast-copy (fetched 2026-08-29T12:36:23.260710+00:00, sha b25fbc97ec66)
- Data as of 2026-08-30T08:39:29.467469+00:00.