Polyfills and shims

12-month change compares the average of the last 4 weeks of downloads with the first 4 weeks of the 52-week series. Gzip size is for the whole package, as measured by Bundlephobia. "-" means the value has not been fetched.

• @ant-design/create-react-contextA fork of create-react-context in MIT license
• string.prototype.startswithA robust & optimized `String.prototype.startsWith` polyfill, based on the ECMAScript 6 specification.
• element-closest-polyfillA minimal polyfill for Element.closest
• @cto.af/textdecoderQuick wrapper that finds TextDecoder in your runtime, or uses an adequate polyfill
• navigator.sendbeaconPolyfill for navigator.sendBeacon()
• document-register-elementA stand-alone working lightweight version of the W3C Custom Elements specification
• @stdlib/math-base-special-acosCompute the arccosine of a double-precision floating-point number.
• array.prototype.foreachAn ES spec-compliant `Array.prototype.forEach` shim/polyfill/replacement that works as far down as ES3.
• ember-destroyable-polyfillPolyfill for RFC 580: Destroyables
• proxy-polyfillPolyfill for the Proxy object
• es6-promise-polyfillPolyfill for ES6 Promise
• fs-remove-compatCross-platform file removal utilities with Node.js 0.8+ compatibility. Provides rm and rmSync ponyfills matching Node.js fs.rm API, plus safeRm/safeRmSync with Windows-friendly retry defaults.
• dynamic-import-polyfillA polyfill for the native import() in the browser
• @webcomponents/scoped-custom-element-registryScoped CustomElementRegistry Polyfill
• xmldom-qsaBased on @xmldom/xmldom with some minor enhancements. Add querySelector, querySelectorAll and match method to Document and Element.
• transit-jsTransit is a data format and a set of libraries for conveying values between applications written in different languages. This library provides support for marshalling Transit data to/from Javascript.
• @zenfs/streamsA modern node:stream polyfill
• @ungap/custom-elementsAll inclusive customElements polyfill for every browser
• @mcp-b/globalW3C Web Model Context Protocol (WebMCP) API polyfill. Let AI agents like Claude, ChatGPT, and Gemini interact with your website via document.modelContext.
• hyperformCapture form validation back from the browser
• object-assign-polyfillSimple ES6 Object.assign() polyfill for older environments.
• visibilityjsWrapper for the Page Visibility API
• cross-fetch-ponyfillFetch polyfilled in Node only
• @fastly/performance-observer-polyfill<h1 align="center" style="border-bottom: none;">🔎 PerformanceObserver Polyfill</h1> <p align="center"> <a href="https://travis-ci.org/fastly/performance-observer-polyfill"> <img alt="Travis" src="https://img.shields.io/travis/fastly/performance-obs
• promise.tryES Proposal spec-compliant shim for Promise.try
• keyboardevent-key-polyfillpolyfill for `KeyboardEvent.prototype.key`
• ember-cached-decorator-polyfillPolyfill for RFC 566: @cached
• focus-options-polyfillJavaScript polyfill for the WHATWG spec of focusOptions, that enables a set of options to be passed to the focus method.
• broadcastchannel-polyfillPolyfill for BroadcastChannel for Safari, old Chrome and Opera
• error-causeAn ES-spec-compliant shim/polyfill/replacement for the `.cause` property on all Error types that works as far down as ES3
• @stdlib/utils-index-ofReturn the first index at which a given element can be found.
• fs-copy-file-syncfs.copyFileSync ponyfill
• @expo/browser-polyfillBrowser polyfill for making React Native compatible with web libs like pixi.js, three.js, phaser.js
• function.name-polyfillPolyfill for the basic functionality of `Function.name` accessor property in its pre-ES6 form
• @oddbird/css-anchor-positioningPolyfill for the proposed CSS anchor positioning spec
• compression-streams-polyfillLightweight polyfill/ponyfill for the Compression Streams API
• webassemblyjsWebAssembly interpreter
• bluebird-globalPatches global.Promise to use bluebird and returns a bluebird instance
• mobile-drag-dropPolyfill for making HTML5 drag and drop possible in all browsers.
• sugarA Javascript utility library for working with native objects.
• browserify-shimMakes CommonJS-incompatible modules browserifyable.
• disposablestackAn ESnext spec-compliant `DisposableStack`, `AsyncDisposableStack`, `Symbol.dispose`, and `Symbol.asyncDispose` shim/polyfill/replacement that works as far down as ES3.
• suppressed-errorES Proposal spec-compliant shim for SuppressedError
• utils-indexofReturns the first index at which a given element can be found.
• ember-assign-polyfillA polyfill for Ember.assign in <= 2.4
• @inrupt/jest-jsdom-polyfillsThis package provides various polyfills needed on jest/jsdom when using the Inrupt SDKs
• error-polyfillJavascript Error Polyfill
• scroll-behavior-polyfillA polyfill for the 'scroll-behavior' CSS-property
• indexeddbshimA polyfill for IndexedDB using WebSql
• frontend-collective-react-dnd-scrollzoneA cross browser solution to scrolling during drag and drop.

• scroll-into-view-if-needed vs @juggle/resize-observer
• css-vars-ponyfill vs object-fit-images