Web Animations API
The bridge between CSS animations and JavaScript control. Required for complex choreography, scroll-driven animations, and animation libraries (GSAP, Motion One) that target this API.
What It Defines
Unifies CSS Animations, CSS Transitions, and programmatic animation under one API. Defines the Animation interface, KeyframeEffect, animation timelines, playback control (play, pause, reverse, playbackRate), and the relationship between CSS and JS animation models.
Canonical (Normative)
Convenient (Practical)
Publishes web platform specs including CSS, accessibility, security policies, Service Workers, Web App Manifest, and many browser APIs. Also maintains some versioned HTML/DOM specs.
Related Specs
CSS drives all visual layout. Key modules: Grid, Flexbox, Custom Properties, Cascade layers, Container Queries. The snapshot identifies what's stable vs experimental.
Every frontend framework (React, Vue, Svelte) ultimately produces DOM operations. Understanding the event model and tree structure prevents subtle bugs.