# chancejs/chancejs

Chance - Random generator helper for JavaScript

Repository: https://github.com/chancejs/chancejs
Canonical: https://ross.abutalabs.com/products/chancejs
Homepage: http://chancejs.com
Language: JavaScript
License: MIT
License Family: permissive
Topics: chance, javascript, random
Last push: 2025-05-18T21:03:04+00:00

## Health v2 (maintenance only)
Score: 42/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 22, release rhythm 35, longevity 100
- inputs: {"age_days": 4822, "days_push": 472, "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 6540, forks 462 (observed 2026-08-28T04:09:45.050465+00:00)

## What it is
Chance is a minimalist JavaScript library for generating random strings, numbers, names, addresses, dates, and other data, built on a seedable Mersenne Twister for reproducibility. It is primarily used to reduce monotony when writing automated tests or generating mock data.

## Use cases
- generate fake user data for tests
- seed random data generator for reproducible tests
- generate random names and addresses in javascript
- mock api response data
- generate random strings and numbers in node
- populate json schema with sample data

## When to choose
- you need random test or mock data in JavaScript with optional seeding for repeatability
- you want a lightweight, dependency-free generator covering names, addresses, finance, web, and time data
- you need browser and Node support from a single library

## When to avoid
- you need cryptographically secure randomness
- you need locale-specific fake data beyond what Chance provides
- you are not working in JavaScript

## Facets
- artifact type: library
- maturity: maintenance
- function: data-generation, sdk
- domain: developer-tools, testing
- platform: browser, cross-platform
- tags: fake-data, random-generator, mock-data, seeded-random, mersenne-twister, test-data, automation, nodejs, javascript

## Member repositories
- chancejs/chancejs (main) score 42

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:45.050465+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 2026-08-29T17:44:06.931930+00:00, confidence not recorded.
  - readme: https://github.com/chancejs/chancejs (fetched 2026-08-28T04:09:45.050465+00:00, sha bd8d5f410296)
  - homepage: http://chancejs.com (fetched 2026-08-29T08:40:40.578298+00:00, sha 42755ed76138)
- Data as of 2026-08-30T08:39:29.467469+00:00.