# gildas-lormeau/zip.js

JavaScript library to zip and unzip files supporting parallel compression, web streams, pluggable compression engines, zip64, split files, data encryption, and deflate64 decompression.

Repository: https://github.com/gildas-lormeau/zip.js
Canonical: https://ross.abutalabs.com/products/zipjs
Homepage: https://gildas-lormeau.github.io/zip.js
Language: JavaScript
License: BSD-3-Clause
License Family: permissive
Topics: zip, javascript, zip64, browser, unzip, zipcrypto, deno, aes-encryption, nodejs, multi-core, compression-stream, transform-stream, web-worker, web-stream, service-worker, split-zip, zip-encryption, multicore, usdz, deflate64
Last push: 2026-08-25T20:25:24+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 87, longevity 100
- inputs: {"age_days": 5498, "days_push": 8, "days_rel": 8, "gap_med": 1.0, "n_releases_24m": 79}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3879, forks 548 (observed 2026-08-28T04:08:27.971896+00:00)

## What it is
zip.js is a BSD-3-Clause JavaScript library for creating and reading zip archives in browsers, Node.js, Deno, and Bun. It supports Zip64, AES and ZipCrypto encryption, multi-core compression via web workers, web streams, pluggable compression engines, and split archives with no third-party dependencies.

## Use cases
- create zip files in the browser with javascript
- unzip archives in node.js or deno
- compress files in parallel using multiple cores
- read or write zip archives larger than 4GB with zip64
- encrypt zip entries with AES or ZipCrypto
- stream zip data incrementally with web streams
- create split zip archives

## When to choose
- you need zip support across browsers and server-side runtimes with one library
- you must handle very large archives or split files
- you need encrypted zip entries (WinZIP AES or ZipCrypto)
- you want zero third-party dependencies and stream-based APIs

## When to avoid
- you need formats other than zip such as tar, 7z, or rar
- you need a simple synchronous API without streams or promises
- you target very old browsers lacking Promise, TypedArray, or Streams APIs

## Facets
- artifact type: library
- maturity: active
- function: compression, file-system, cryptography, concurrency
- domain: files, web-development, developer-tools
- platform: browser, bun, cross-platform
- tags: zip, zip64, unzip, web-streams, web-workers, aes-encryption, deflate64, split-zip, no-dependencies, nodejs, deno

## Member repositories
- gildas-lormeau/zip.js (main) score 95

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:27.971896+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 2026-08-29T18:25:43.904775+00:00, confidence not recorded.
  - readme: https://github.com/gildas-lormeau/zip.js (fetched 2026-08-28T04:08:27.971896+00:00, sha d444f69b36ff)
  - homepage: https://gildas-lormeau.github.io/zip.js (fetched 2026-08-29T09:20:06.422125+00:00, sha 80006ebc2c2a)
- Data as of 2026-08-30T08:39:29.467469+00:00.