sindresorhus/on-change
Some data may be outdated — see provenance labels.
Watch an object or array for changes observed · 2026-09-28
Health v2 · maintenance only
80/100
- Activity 95
- Release rhythm 49
- Longevity 100
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-10-21. Adoption (stars, forks) is never an input.
- gap_med: 65.0
- age_days: 3235
- days_rel: 261
- days_push: 32
- n_releases_24m: 3
Adoption not part of the score
2029 stars · 87 forks observed · 2026-09-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded
A tiny JavaScript library that watches objects and arrays for changes using the ES2015 Proxy API. It recursively detects deep mutations and invokes a callback with the change path, new value, previous value, and method data.
Use cases
- watch javascript object for changes
- detect deep property mutations in an object
- observe array changes like push or splice
- build reactive state without a framework
- track which object paths were modified
- unsubscribe from object change notifications
When to choose
- you need lightweight change detection for plain objects and arrays
- you want deep, recursive observation with change paths
- you're in a modern environment supporting ES2015 Proxy
When to avoid
- you need to support environments without Proxy (older browsers)
- you need a full reactive state management system with stores and subscriptions
- you need to observe non-object types or class instances with private fields
Facets
library · maturity stable
state-management developer-tools web-development frontend developer-tools browser proxy observer change-detection es2015-proxy npm-package nodejs javascript
2 sources
- readme: https://github.com/sindresorhus/on-change · fetched 2026-09-28 · 430b1cc65446
- registry_npm: https://registry.npmjs.org/on-change · fetched 2026-08-29 · 4b16cff73707
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| sindresorhus/on-change | main | 80 |
For agents
markdown · JSON · MCP: product_card(name="sindresorhus/on-change")
Data as of 2026-10-19T08:05:51.212177+00:00 · Report a problem