# ljharb/qs

A querystring parser and serializer with nesting support

Repository: https://github.com/ljharb/qs
Canonical: https://ross.abutalabs.com/products/qs
Language: JavaScript
License: BSD-3-Clause
License Family: permissive
Topics: javascript, encoding, querystrings, nodejs, node, browsers, url-parsing, stringify, parse
Last push: 2026-07-11T06:16:59+00:00

## Health v2 (maintenance only)
Score: 74/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 92, release rhythm 35, longevity 100
- inputs: {"age_days": 4422, "days_push": 53, "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 8943, forks 918 (observed 2026-08-28T04:10:26.370182+00:00)

## What it is
qs is a JavaScript library for parsing and serializing URL querystrings, with support for nested objects and arrays via bracket notation. It includes security features such as depth limits and prototype pollution protection.

## Use cases
- parse query strings into nested objects
- serialize objects into query strings
- handle arrays in URL parameters
- safely parse untrusted querystring input
- convert URL parameters to JavaScript objects

## When to choose
- you need nested object or array support in querystrings
- you want battle-tested parsing with security limits
- you need consistent behavior across Node.js and browsers

## When to avoid
- you only need simple flat key-value parsing (URLSearchParams suffices)
- you need querystring handling outside the JavaScript ecosystem

## Facets
- artifact type: library
- maturity: stable
- function: parser, serialization
- domain: web-development, developer-tools
- platform: browser
- tags: querystring, url-parsing, stringify, nested-objects, arrays, nodejs, javascript

## Member repositories
- ljharb/qs (main) score 74

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:10:26.370182+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 2026-08-29T17:24:31.553444+00:00, confidence not recorded.
  - readme: https://github.com/ljharb/qs (fetched 2026-08-28T04:10:26.370182+00:00, sha a147917bc399)
  - registry_npm: https://registry.npmjs.org/qs (fetched 2026-08-29T08:25:01.147008+00:00, sha f9b88040ab5a)
- Data as of 2026-08-30T08:39:29.467469+00:00.