# web-animations/web-animations-js

JavaScript implementation of the Web Animations API

Repository: https://github.com/web-animations/web-animations-js
Canonical: https://ross.abutalabs.com/products/web-animations-js
Homepage: http://web-animations.github.io
Language: JavaScript
License: Apache-2.0
License Family: permissive
Last push: 2021-06-20T11:58:39+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 4311, "days_push": 1900, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3775, forks 402 (observed 2026-08-28T04:08:18.248572+00:00)

## What it is
A JavaScript polyfill implementing the Web Animations API for browsers that lack native support, falling back to native implementations when available. It unifies SVG and CSS animation features into a single programmatic API.

## Use cases
- animate DOM elements with element.animate() in older browsers
- polyfill the Web Animations API for cross-browser support
- create programmatic fade and scale animations
- drive high-performance animations from JavaScript
- support legacy browsers lacking native Web Animations

## When to choose
- you need Web Animations API support in older or non-supporting browsers
- you want a polyfill that defers to native implementations when available
- you need programmatic control over CSS/SVG-style animations

## When to avoid
- you only target modern browsers with native Web Animations API support
- you need a full animation library with easing presets and timelines
- you need actively developed features - the project is in maintenance mode

## Facets
- artifact type: library
- maturity: maintenance
- function: animation, ui-components
- domain: web-development, frontend
- platform: browser
- tags: polyfill, web-animations-api, browser-compatibility, javascript

## Member repositories
- web-animations/web-animations-js (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:18.248572+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 2026-08-29T18:27:50.440052+00:00, confidence not recorded.
  - readme: https://github.com/web-animations/web-animations-js (fetched 2026-08-28T04:08:18.248572+00:00, sha eaad72c9c3ef)
  - registry_npm: https://registry.npmjs.org/web-animations-js (fetched 2026-08-29T09:22:46.397355+00:00, sha ec214007101e)
- Data as of 2026-08-30T08:39:29.467469+00:00.