Polyfills the ResizeObserver API.

📋 Simple copying on the web, with maximum browser compatibility. (You probably don't need this anymore!)

Web Streams, based on the WHATWG spec reference implementation

Spec-compliant FormData implementation for Node.js

🎙MediaRecorder ponyfill that records audio as mp3

Universal LocalStorage for browser and Node.js.

(A smaller) polyfill for the react context API

A window.resizeTo polyfill for test environments like Jest & JSDOM (in <10 LoC)

A tiny, zero-dependency yet spec-compliant asynchronous iterator polyfill/ponyfill for ReadableStreams.

A ponyfill/polyfill for VideoPlaybackQuality.

A ponyfill for fs.readdir(path, { withFileTypes: true })

Obsolete wrapper around fetch-ponyfill

marquee(跑马灯) ponyfill using web components

Standalone zero-dependency implementation of the entire `Math` namespace, compatible with any JS runtime.

Shim for `import.meta.resolve`.

Preconfigured Promise ponyfill based on promise-polyfill and setasap

A tiny grayscale image ponyfill for IE 10/11

🧰 node:util for use anywhere