# codemix/fast.js

Faster user-land reimplementations for several common builtin native JavaScript functions.

Repository: https://github.com/codemix/fast.js
Canonical: https://ross.abutalabs.com/products/fastjs
Language: JavaScript
License: MIT
License Family: permissive
Last push: 2019-01-17T16:56:13+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4453, "days_push": 2785, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3382, forks 111 (observed 2026-08-28T04:07:58.664628+00:00)

## What it is
fast.js is a JavaScript library providing faster user-land reimplementations of common native built-in functions like forEach, map, and reduce, optimized for the V8 engine. It achieves speedups by skipping rarely-used ECMAScript edge cases such as sparse array handling.

## Use cases
- speed up array iteration in node.js
- replace slow native forEach and map calls
- optimize hot loops in JavaScript code
- benchmark native methods against JS reimplementations
- clone objects and arrays faster

## When to choose
- you run on V8 (node.js or chrome) and need maximum iteration performance
- your code has no sparse arrays and doesn't need full spec compliance
- you're profiling a hot path where native methods are a bottleneck

## When to avoid
- you need 100% ECMAScript spec compliance or a drop-in replacement
- you target non-V8 JavaScript engines or browsers
- you want an actively maintained library - the last release was 2019

## Facets
- artifact type: library
- maturity: abandoned
- function: benchmarking, developer-tools
- domain: performance, developer-tools, web-development
- platform: -
- tags: micro-optimization, array-methods, v8, utility-library, nodejs, javascript

## Member repositories
- codemix/fast.js (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:58.664628+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 2026-08-29T18:39:40.174877+00:00, confidence not recorded.
  - readme: https://github.com/codemix/fast.js (fetched 2026-08-28T04:07:58.664628+00:00, sha c084ab5bc306)
  - registry_npm: https://registry.npmjs.org/fast.js (fetched 2026-08-29T09:33:19.443543+00:00, sha b80e2372cc8f)
- Data as of 2026-08-30T08:39:29.467469+00:00.